Harley Hahn's
Internet Insecurity

Chapter 3...

Staying One Step Ahead

Some Web Terminology

You may not know it, but each time you use the Web, your browser builds trails of information documenting your activities. A knowledgeable person with access to your computer can easily follow those trails and figure out what you have been doing. (I have had to perform such investigations myself on occasion.) In a moment, I will explain how this works, and then I'll show you how to protect your privacy. However, before we can do that, we need to discuss a few important technical terms.

No doubt you have seen many Web addresses in the form:


For example, the address of my Web site is:


The technical name for this type of Web address is a URL, which stands for "Uniform Resource Locator". (You pronounce the name as three separate letters: "U-R-L".) As the name implies, the purpose of a URL is to provide a uniform way to locate an Internet resource.

Most of the time, we use URLs to specify the addresses of Web pages. The URL above, for example, specifies the address of my Web site. However, URLs were designed to be a general specification that could be used to indicate any type of Internet resource. For instance, the following URL specifies the email address of the President of the United States:


Compare the two URLs:


The first one refers to a Web page, the second one to an email address. As you can see, the first part of a URL tells you what type of resource the URL refers to. This designation is called the SCHEME. In our examples, the scheme of the first URL is http (which indicates a Web page); the scheme of the second URL is mailto (which indicates an email address). There are other schemes as well, but you won't see them much, so let's not worry about them.

Within a URL, the scheme is always followed by a colon (:) and, in some cases, two slashes (//). The two slashes are a technical designation to indicate that the resource resides on a specific computer. Web pages always exist on a specific computer, so Web addresses always contain the two slashes. Email addresses, on the other hand, do not represent resources that exist on a specific computer, so they do not have the two slashes. Although the technical distinction may seem irrelevant to you, it is important to your browser when it is called upon to interpret a particular URL, so the two slashes are important.

In case you are wondering what http means, here is the explanation.

Web pages can contain text (characters, numbers and punctuation), pictures, sounds, video, and so on. In addition, Web pages can contain LINKS. When you click on a link, it takes you to a different resource, usually another Web page.

When text contains links, we call it HYPERTEXT. The name comes from science fiction stories, in which rocket ships can travel very large distances in a short time by jumping through "hyperspace". When you are reading a Web page and you click on a link, it looks as if you are jumping from one Web page to another, hence the name hypertext.

The system used to transport Web data on the Net is called HTTP, which stands for "Hypertext Transport Protocol". For this reason, when a URL refers to a Web page, the URL will have the scheme http. (In retrospect, perhaps web would have been a better choice.)

Originally, URLs were conceived as a way to refer to various types of Internet resources. However, the Web has become so dominant that virtually all the URLs you will ever use refer to Web pages. Since all of these start with http://, your browser lets you leave out this part when you type a Web address.

For example, as far as your browser is concerned, the following two Web addresses both refer to the same resource:


Only the first address is a proper URL, but if you type the second one, your browser will change it to the proper format automatically.

In other words, whenever you type an address that does not start with a scheme, your browser will assume it refers to a Web address and insert the http:// for you.

Before we finish this section, I want to discuss just a few more technical terms. These are words I am sure you have seen, but I want you to appreciate their meanings precisely.

As I mentioned, hypertext is data that contains links to other data and resources. The basic job of your browser is to request a file containing hypertext and then display it on your computer. When such a file is displayed, what you see is called a WEB PAGE. In this sense, the word "page" is just a metaphor that has nothing to do with printed pages. A Web page can be any length, often much longer than a normal printed page.

A collection of related Web pages, maintained by a person or an organization, is called a WEB SITE (sometimes written as one word, WEBSITE). A Web site can contain any number of pages: some large Web sites have hundreds of Web pages, while a few small sites consist of only a single page.

Virtually all Web sites are organized so as to have one special page that acts as the door to the Web site. This page, called the HOME PAGE, is designed to be the first page you see when you visit the site. For example, if you were to give your browser the address of my Web site, you would see the home page that I designed for people visiting the site. A home page, like any Web page, can contain text, pictures, links, sounds, video, and so on. Typically, however, home pages are designed to introduce the Web site and to help people find what they want.

Just so your aren't confused, the term "home page" has another, completely different meaning. When you first start your browser, it displays a particular Web page automatically. This is your personal home page, and you can change it whenever you want.

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Your Browser History

As you use the Web, there are several ways in which your browser stores information about your activities. These are:

  • History
  • Cache
  • Auto-Complete information (including passwords)
  • Address bar list
  • Radio station list

I'll discuss each one of these in turn, and then show you how to safeguard your privacy as much as possible. As you read, please remember one thing. It's true that you can take steps to erase most of the information that your browser accumulates about what you do on the Web. However, no precautions are foolproof. Your best defense against privacy invasion — and the very best way to stay out of trouble at work — is simple: never use your computer for personal activities.

Each time you visit a new Web page, your browser saves the URL for that page in what is called your HISTORY. Internet Explorer, in particular, keeps a long history, detailing your activities over many days.

Internet Explorer was designed to record your history as a favor to you. Whenever you want, you can click on the History button, display the history, and jump to any URL you want. This feature can come in handy, for example, when you want to look at a Web site that you remember visiting last Tuesday. All you need to do is find it in your history.

On the other hand, anyone who has access to your computer can find out all the Web sites you have visited lately, just by looking at your history. Obviously, this could be trouble for you if your boss finds out that you have been looking at questionable Web sites. However, even if you are a paragon of virtue, your history can get you into trouble by accident.

Suppose, for example, you have a few spare moments before a big meeting, and you decide to take a look at the White House Web site in order to read the latest press releases (a noble and admirable pastime). It happens that the URL for the White House Web site is:


However, by accident, you type:


To your surprise, you find out this is not the White House. In fact, after looking at some pictures of "interns", you realize that this is a porno site! To retype the correct address and jump to the White House Web site is, for you, the work of a moment. However, it is too late. Your visit to the porno site is already recorded in your history, where anyone can find it.

So to be prudent, you take a look at your history and, much to your surprise, you find a whole series of questionable URLs from two days ago. It must have been from the time when you were on your way to lunch, and that nice young man from the accounting department asked if he could use your computer for a few minutes to check a few numbers.

You start to panic. Before you can say "I was framed", your boss is going to drop in on his way to the meeting. You quickly clear the history (I'll show you how it works in a moment), and you go to a Web page showing stock market reports. No sooner does the page appear on your screen when your boss walks in. He looks at your computer, and nods his head approvingly. As the two of you leave your office and walk down the hall, you breathe a sigh of relief. That was a close call, but all's well that ends well. You are safe.

Or so you think. What you don't know is that the nice young man from accounting used your computer to look at pictures of a beautiful young woman having intimate relations with a platypus, and, right now, as you are walking down the hall feeling as confident as a politician with the check in his pocket, a copy of each of those pictures is sitting on your hard disk, accessible to anyone who knows where to look for them.

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Where the Pictures Are: Your Cache

You may have noticed that most Web pages contain a number of elements. To be sure, there will be text, but most pages also have pictures (photos or graphics). Sometimes you will even hear sounds. All of these elements exist in separate files. When your browser contacts the Web site, it asks for whatever is necessary to display a particular page. The Web site sends the appropriate files to your browser, which then puts them together to create the actual Web page.

What happens if you want to view the same page at a later time? Well, your browser could ask the Web site to resend all the files again. However, this would be wasteful. Instead, your browser saves the files on your hard disk in a temporary storage area. Later, if you want to look at the same page again, it is a simple task for your browser to retrieve the files from its storage area and, once again, create the Web page. Moreover, this time, it all happens a lot faster, because the files are already on your computer and don't have to be downloaded (copied) from the Net.

The temporary storage area used by your browser is called a CACHE. Actually, the word "cache" is a general term, referring to a special, easy-to-access storage area used to hold data. Lots of programs use caches, as do various hardware components, such as processors and disk controllers. The idea is to use the cache to hold data that is likely to be needed in the near future.

Think of it this way. Let's say you work in a library, and you notice that a small number of books are very popular. People ask you for them all the time, so instead of putting them on the shelves, you keep these particular books behind the counter. That way, when someone asks for one of the books, you can hand it to him right away. In this case, you are using the storage space behind the counter as a cache.

Of course, out of all the files for all the pages you have viewed, your browser doesn't know which ones you are going to want to see again — so it keeps them all. That means, that when you revisit a Web page, it appears faster the second time than the first time. It also means that, if someone knows where to look on your hard disk, he or she can see everything you have been looking at, particularly the pictures.

This is only possible if someone knows where your cache is. However, Internet Explorer always keeps its cache in the same place: in a sub-folder residing in the Windows folder on your C: drive (hard disk). In a fit of creativity, Microsoft chose to give the cache folder the cunning name of Temporary Internet Files, so the folder is easy to find.

Anyone with access to your computer can see what you have been doing on the Web.

In other words, anyone with access to your computer can see what you have been doing on the Web simply by looking at the files in the folder named:

C:\Windows\Temporary Internet Files

(If you are using Windows 2000 or Windows NT, the location will be a bit different. See Chapter 4 for the details.)

Don't worry if you don't understand the terminology, or if you wouldn't know a folder from a mangel-wurzel. The point is that, technically speaking, it's an easy thing to do, and that anyone who understands the Windows file system can do it if he or she gets access to your computer. Moreover, such a person would not necessarily have to be in your office. He or she might be able to access your computer from another location on the company network.

So, how do you safeguard your privacy? You empty your cache regularly. When you do this, we say that you FLUSH the cache. (I'll show you how to do it later in the chapter.)

Before we leave this section, I want to go back to a technical term I used a moment ago, when I talked about copying data from the Net. The term is DOWNLOADING.

Downloading refers to copying information from the Internet to your computer. When you copy information from your computer to the Internet, it is called UPLOADING. When you first encounter these terms, it's easy to get them confused, so here is an easy way to remember. Just imagine the Internet floating above you in the sky. Data from the Net comes down, while data going to the Net must go up.

(At this point, if you recall the section in Chapter 1 in which I discussed how the Net is a large, unfathomable entity of enormous importance to human beings, you might want to take a moment and reflect on the similarity between the Internet and God.)

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Have you ever known someone whose mind raced so fast that he didn't have the patience to wait for people to talk at their own speed? For example, you are delivering a report during an important meeting, "...and so I sent the order to the Bumble—", when Mr. Know-it-all completes your sentence for you, "—Yes, yes, yes, the Bumblethorpe Company."

Well, computers are fast, and when it comes to certain types of information, they can certainly be programmed to be know-it-alls. This is the case with Internet Explorer, which has a feature called AUTOCOMPLETE. Whenever you are called upon to type some information, the browser watches what you are doing and tries to complete it for you.

For example, let's say that last week you visited my Web site, and today, you want to visit it again. You click on the ADDRESS BAR (the empty area to the right of the word Address) and you start to type the URL:


At this point, the browser guesses what you are doing and completes the address for you:


It also shows you a list of similar URLs that you have visited in the past.

You now have three choices. First, you can press the Enter key. This signals that you want to accept the browser's suggestion. Second, you can select one of the URLs from the list, if that's what you want. Or, if you don't like your browser's suggestion, you can keep typing and override it.

How does AutoComplete work? Whenever you type a URL into the Address Bar, fill out a form, or enter a password, the browser saves the information. Later, when you type something new, the browser can make suggestions based on the data you entered previously.

The AutoComplete feature can be useful, but it does create a privacy problem for you. Anyone who uses your browser will see the same list of choices that you do. In the example I gave above, this means that someone who is typing a URL into the Address Bar will, all of a sudden, be presented with a list of URLs you have typed.

Moreover, Internet Explorer has an interesting shortcut that also presents a privacy problem. If you press the F4 key, the browser will show you the complete list of everything you have typed into the Address Bar. You can then press the Down Arrow or PageDown keys to scroll through the list. (Note: When you type a URL, AutoComplete looks for possible matches. To do so, it compares what you are typing to all the addresses you have ever typed into the Address Bar, as well as all the URLs of pages you have visited by clicking on links. When you press F4, the browser shows you only those addresses that you yourself typed into the Address Bar.)

Most people don't know about this trick, so if you want to look cool and impress someone, walk up when they have their browser open, press F4, and start looking through the list of addresses. Hint: This is a great way to make friends, when it is your first day on a new job.

AutoComplete also remembers passwords, which poses a particularly important problem. If you use the Web much, you'll end up with a number of favorite sites that require you to enter a user name and password. Internet Explorer will remember such information for you, but it will also expose you to other people being able to log in under your name, if they can access your browser.

As a safety feature, when your browser inserts a password for you, it will not display the actual characters. When you press Enter to submit the information, the real password will be sent. However, on your screen, you will only see asterisks (******). But, don't feel too safe. If someone can get to your computer when you are not around, he can use AutoComplete to log in to your favorite Web sites under your name, even if he can't see the real password. Moreover, there are free programs that anyone can download that will show a password, even when your browser displays asterisks.

AutoComplete is a feature that permeates the Microsoft way of thinking, and you will find variations all over the place. For example, if you use Microsoft Word or Excel, the program will save a list of your most recently accessed documents and spreadsheets. (Just pull down the File menu.) You will also find AutoComplete-like assistance inside of Windows Explorer (the Windows file manager).

One last example: Within Internet Explorer, there is a built-in toolbar to make it easy to listen to radio stations around the world. (Pull down the View menu, select Toolbars, and then click on Radio.) Within the Radio toolbar, there is a button named Radio Stations. When you click on this button, the browser will show you a list of the last few stations you have accessed. Even if you clear out all URLs, all the form information and all the passwords, Internet Explorer will not clear the radio station list.

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Controlling Your Browser History

So far, we have discussed three ways by which your browser monitors what you do and records your actions: the history, the cache, and AutoComplete. To safeguard your privacy, you need to be able to turn these services off and on, and clear out the data storage whenever you want. Each of these features works differently, so I'm going to cover them one by one, starting with the history. (Note: The instructions I will give you are for Internet Explorer. The details may vary a bit on your computer, depending on what version of the program you are using.)

To control your history, pull down the Tools menu and select Internet Options. This will open a new window. The various types of options are displayed in separate "pages". To move from one page to another, click the appropriate tab near the top of the window. When you are finished using this window, you can close it by clicking on the OK button.

When you first open the Internet Options window, you will see the General page, and that is the one we want to control the history. Look at the History section, and you will see that you can do two things. First, you can click on the Clear History button. That deletes all the URLs of the Web pages you have viewed. It also deletes all the addresses used by the AutoComplete feature.

Second, you can control the number of days that URLs are kept in the history. To do this, simply change the number. However, you should be aware that setting the number to 0 will not keep Internet Explorer from creating a history. Sorry, but Microsoft in their infinite wisdom has decreed that you can't turn off this feature.

When you are finished, click on the OK button to close the Internet Options window.

If you want, there is a way to selectively delete part of your history. Open the history by clicking on the History button. You can now right-click on any item and choose Delete from the pop-up menu.

Internet Explorer keeps your history in the folder:


(If you are using Windows 2000 or Windows NT, the location will be a bit different. See Chapter 4 for the details.)

If you know how to use Windows Explorer (which I'll discuss later in the chapter), you can navigate to this directory and clean it out yourself. Although there is no real advantage to doing this — compared to clearing out the history from within Internet Explorer — showing that you know how to use Windows Explorer is a good way to impress someone on a first date.

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Controlling AutoComplete

To control the AutoComplete feature, pull down the Tools menu and select Internet Options. This will open a new window. Click on the Content tab near the top of this window. Within the "Personal information" section, click on the AutoComplete button. You will now see another window containing the settings that allow you to control AutoComplete.

There are two things you can do. First, you can specify what type of AutoComplete information your browser should maintain. There are three types of information:

  • Web addresses (when you type a URL in the Address bar)
  • Forms (when a Web page asks you to specify information)
  • User names and passwords

You can turn each of these off and on as you wish. For maximum privacy, turn them all off. If you don't turn them all off, you can maintain your privacy by deleting whatever AutoComplete information has accumulated.

To delete the Web address information, you clear the history, as I described in the previous section.

To delete the information that you have typed into forms, click on the Clear Forms button.

To delete all the passwords you have entered, click on the Clear Passwords button.

When you are finished, click on the OK button to close this window. Then click on the OK button to close the Internet Options window.

Aside from the AutoComplete options I just described, there are two more options in a completely different location. To see these options, you start the same way: pull down the Tools menu and select Internet Options. This time, however, click on the Advanced tab. Within the Settings box, scroll down to the bottom of the Browsing section. You will see two settings related to AutoControl, which you can turn on or off.

The first setting is "Use inline AutoComplete for Web Addresses". This setting controls whether or not AutoComplete is active when you type a URL into the Address Bar.

You might ask, what is the difference between this off/on switch and the other off/on switch, the one you access via the Content page? The difference is subtle. This switch tells the browser to complete a URL for you as you type it in the Address Bar. The other switch tells the browser not only to complete the URL, but also to show you a list of similar URLs that you have previously typed.

I know this is confusing (and the next time I see Bill Gates, you can be sure I will mention it). Just think of it this way: if you want to inactivate AutoComplete, you need to turn off two separate switches.

The second AutoComplete setting on the Advanced page is "Use inline AutoComplete in Windows Explorer". (We'll talk about Windows Explorer in the next section.) This setting is supposed to allow you to turn on or off the AutoComplete feature when you type the name of one of your folders or files into the Internet Explorer Address Bar. I say "supposed to", because this option doesn't really do much of anything, so you can ignore it.

(Again, this is something I am going to have to mention to Bill Gates.)

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Disks and Discs

At this point, I would like to introduce you to an important tool called Windows Explorer, the program that you use to manipulate the files and folders on your computer. However, before we get to the details, I need to cover some background material, starting with disks: the devices that are used to store data on your computer.

Long-term data storage is supplied by various types of DISKS (sometimes referred to as DISCS), the most important of which are floppy disks, hard disks and CDs.

To understand the floppy/hard disk terminology, we have to go back to August 1981, when IBM introduced the first PC. At the time, the only permanent data storage was provided by large (5.25 inches), thin, removable disks. These disks were flexible and, as such, were called FLOPPY DISKS or FLOPPIES. In August 1984, the IBM PC AT computer introduced a new type of floppy disk. The new floppy was smaller, 3.5 inches, could hold more data, and was encased in a hard protective plastic shell. Since then, floppy disk technology has improved, but the basic design hasn't changed much. Today's floppies look pretty much the same as they did in 1984.

The reason that floppy disk technology hasn't changed all that much is because, early on, it was overtaken by a more important technology. In March 1982, IBM announced the PC XT, the first personal computer with a HARD DISK. This was a medium-sized box inside the computer, that provided a large amount of fast, permanent data storage. This device was faster and could hold a lot more data than a floppy disk. Today, all computers have a hard disk; in fact, the hard disk on your computer is where all your programs and data are stored. The name "hard disk" comes from the fact that, inside the device, data is stored on several hard, disc-shaped plates.

Although a modern floppy disk has a hard shell, if you break it open, you will see that, inside, the data is stored on a very thin, round, brown surface that is, indeed, floppy. (If you have never opened a floppy disk, you should do so, just for fun. Find an old floppy that you can afford to throw away, and put a label on it that says "Nuclear Research Data". Then gather a bunch of people around you and say, "Have you ever wondered what is inside of these things?", and rip open the plastic shell. Your friends will be more impressed than you can imagine.)

If you work in a company with a network, there is a good chance that all or part of your disk storage is provided centrally, by a FILE SERVER. A file server is a special computer with a large amount of disk storage, that is made available to the various users on the network. The advantage of file servers — large networks might have several of them — is that they can be set up to be fast and extra reliable. Moreover, because they are maintained centrally, they can be backed up regularly by the network administrator.

The third important type of data storage is provided by CDs. Although all CDs look the same, there are actually five different types that are used with computers.

First, there are regular music CDs, the type that were originally designed for CD players. Modern computers can read such discs and play music from them.

Second, there are CD-ROMs. These are CDs that hold computer data. When you buy a program that comes on a CD, you are getting a CD-ROM. (The name stands for "read-only memory", an old-fashioned term that indicates that the data is permanent and can't be changed.)

The third type of CD is the DVD. This type of CD is used to distribute movies. Originally, the name stood for Digital Video Disc, but for marketing reasons, the DVD industry changed the name to Digital Versatile Disc.

The last two types of CDs are CD-Rs and CD-RWs. (The names stand for "readable" and "rewritable".) Both CD-Rs and CD-RWs are used to create your own CDs. The different is that CD-Rs are cheaper, but you can only write on them once. Once you put data on them, the data can be deleted, but not changed. You use CD-Rs when you want to create your own music CDs or CD-ROMs.

CD-RWs cost more than CD-Rs, but you can change the data as much as you want. Thus, they provide long-term, removable storage, sort of like super floppy disks. This makes them perfect for storing backups (copies) of important data. You can copy important data to a CD-RW, and then store the disc in a safe place away from the computer.

The device that reads and writes data to a disk is called a DRIVE. Most computers come with a floppy disk drive and a CD drive. Consumer-oriented computers, such as the ones that are sold in stores, come with a CD drive that reads music CDs, CD-ROMs and DVDs. Professional computers, such as the ones used in companies, don't usually have DVD capabilities.

In all computers, it takes a special type of CD drive, called a CD-RW drive, to read and write CD-Rs and CD-RWs. Some computers come with such a drive, although many do not. If your computer doesn't have one, you will have to add the drive yourself. If you are buying a new computer, a CD-RW drive is definitely something you should have, because it will allow you to make your own music CDs and use CD-RWs for backups.

Note: When we talk about floppies and hard disks, we refer to them as disks. This dates back to the early 1980s, when IBM referred to floppy disks as "diskettes". When we talk about CDs, however, we call them discs.

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How Data Is Measured on a Disk

We measure the storage capacity of a disk in BYTES. Without getting too technical, we can say that 1 byte can hold 1 character of data. Thus, to store the name of my cat, "The Little Nipper", would require 17 bytes. (Each space counts as a single character.) Storing numbers is a bit different, and again I don't want to be too technical. As a general rule, it takes either 2 or 4 bytes to store a number, depending on the size of the number.

Disks can hold millions or billions of bytes, so to make it easy, we use the prefixes from the metric system. The ones we use the most are the abbreviations for thousand, million and billion:

1 KB = 1 kilobyte = 1,000 bytes
1 MB = 1 megabyte = 1,000,000 bytes
1 GB = 1 gigabyte = 1,000,000,000 bytes

In the PC world, typical hard disks come in sizes from 30 GB to 100 GB (30 to 100 billion bytes). To put this in perspective, the very first PC, in 1981, came with floppy disks that could hold 360 KB (360 thousand bytes). In 1982, the very first PC hard disk could store 10 MB (10 million bytes) of data.

The amount of data a CD can hold depends on the type of CD. Music CDs hold 740 MBs of data. DVDs hold a lot more, from 4.4 to 15.9 GB, depending on the type of DVD.

CD-RWs and CD-Rs can hold 650 MB of data. However, before CD-RWs can be used, the discs must be prepared in a certain way (called FORMATTING), which takes up some of the space. A formatted CD-RW can hold 530 MB of data (which is still a lot).

Floppy disks hold 1.44 MB, which hasn't changed for years. Because hard disk and CD technology developed so quickly in the mid-1980s, there wasn't a need to enhance the storage capacity of the standard floppy.

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Strange Metric Terminology

In the previous section, I talked about the metric terminology we use to describe the storage capacity of disks. We talked about kilobytes, megabytes and gigabytes. Just for fun, I thought you might be interested in seeing how high the terminology can take us. Here's a complete list:

1 Kilobyte = thousand bytes
— 1,000 bytes

1 Megabyte = million bytes
— 1,000,000 bytes

1 Gigabyte = billion bytes
— 1,000,000,000 bytes

1 Terabyte = trillion bytes
— 1,000,000,000,000 bytes

1 Petabyte = quadrillion bytes
— 1,000,000,000,000,000 bytes

1 Exabyte = quintillion bytes
— 1,000,000,000,000,000,000 bytes

1 Zettabyte = sextillion bytes
— 1,000,000,000,000,000,000,000 bytes

1 Yottabyte = septillion bytes
— 1,000,000,000,000,000,000,000,000 bytes

At this point, I bet you are asking, what about the very small numbers? Don't they have metric prefixes? They certainly do. To illustrate them, I'll use time measurements: a thousandth of a second is a millisecond, a millionth of a second in a microsecond, and so on.

1 Millisecond = thousandth of a second
— 1/1,000 of a second

1 Microsecond = millionth of a second
— 1/1,000,000 of a second

1 Nanosecond = billionth of a second
— 1/1,000,000,000 of a second

1 Picosecond = trillionth of a second
— 1/1,000,000,000,000 of a second

1 Femtosecond = quadrillionth of a second
— 1/1,000,000,000,000,000 of a second

1 Attosecond = quintillionth of a second
— 1/1,000,000,000,000,000,000 of a second

1 Zeptosecond = sextillionth of a second
— 1/1,000,000,000,000,000,000,000 of a second

1 Yoctosecond = septillionth of a second
— 1/1,000,000,000,000,000,000,000,000 of a second

To understand just how small these numbers really are, consider this. If Bill Gates were to give away a tenth of a penny every femtosecond, he would be completely broke in 99.4 picoseconds.

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Files and Folders

Having strayed for a bit, let's get back on track by discussing Windows Explorer, a tool that helps you maintain the contents of your hard disk. Windows Explorer is important because, when you use the Net, many of the actions you need to take to protect your privacy require you to manipulate files and folders, and to do so, you need to use Windows Explorer.

However, before we can talk about Windows Explorer, I'd like to take a moment to go over the basic ideas concerning files and folders.

On any disk, data is organized into FILES, each of which has a name. File names consist of two parts, separated by a . (period) character. The second part, called the EXTENSION, tells us what type of data is contained in the file. For example, here are two typical file names:


In this case, the extension of the first file is jpg, and the extension of the second file is mp3.

There are a great many different file extensions, most of which you will never have to worry about. The following table shows the most common file extensions and what they mean. Notice that I have also indicated the pronunciation. This is so that, when you talk to people, they will realize you know what you are talking about. Hint: When you pronounce file names, be aware that the period is pronounced as "dot" (just as with Internet addresses). For example, the file names above would be pronounced "harley dot jay-peg" and "happy birthday dot m-p-3".

Extension   Pronunciation           Meaning
html"h-t-m-l"Web page
htm"h-t-m"Web page
asp"a-s-p"Web page generated in special way
gif"giff" or "jiff"Picture stored in GIF format
jpg"jay-peg"Picture stored in JPEG format
txt"t-x-t" or "text"Plain text
zip"zip"Compressed collection of files
exe"e-x-e" or "exy"Executable program
com"comm"Executable program
wav"wave"Sound/music file
mp3"m-p-3" or "em-peg"Music file
doc"doc"Microsoft Word document

A hard disk can hold, literally, tens of thousands of files, far too many to keep track of easily. For this reason, files are organized into what are called FOLDERS or DIRECTORIES. For instance, you might store all your mp3 files in a folder named Music.

To help you organize your files and folders, you can create SUB-FOLDERS (also called SUB-DIRECTORIES) within other folders. For example, let's say you have a great many music files, too many to organize within a single folder. You might create several sub-folders called, Big-band, Jazz, Rock and Classical, and place them within the Music folder. You could then put each music file into the appropriate sub-folder.

With the computer systems that preceded Windows (for example, Unix and DOS), people talked about directories and sub-directories. However, when the first version of Windows debuted (November 1983), Microsoft decided to use the name "folders", which they took from the Macintosh. The choice was based on the belief that most people were not very smart, and the idea of folders would be easier to understand than the idea of directories.

Actually, disk folders are nothing at all like the paper folders we use in an office, and the analogy is actually more confusing than helpful. Still, the name stuck, and today, "folder" and "directory" are synonymous. Hint: If you want to sound like a nerd, talk about directories. If you want to sound like a normal person, talk about folders. If you want to sound really cool, switch back and forth depending on whether or not you are talking to a nerd.

The last thing I want to mention is the way in which we write down a file name. Within this system, we specify the name of the disk on which the file resides, followed by the relevant folder and sub-folders, followed by the name of the file, including the extension. This type of specification is called a PATHNAME or a PATH. Here is an example:


To understand this name, you need to know several things. First, within Windows, each disk has its own name. A disk name consists of a single letter followed by a : (colon) character. The floppy disk is called A:, and the hard disk is C:. (In the olden days, when many computers had two floppy disk drives, the name B: was reserved for a second floppy.) Your CD will probably be D: or E:.

Thus, in the address above, we can see that the file resides on the hard disk named C:.

After the name of the disk comes a series of folders and sub-folders, leading to the one in which the file resides. To separate the disk name and the various folders, we use \ (backslash) characters. (On a standard U.S. keyboard, the backslash is the character above the Enter key.)

So, now you can understand the pathname above. It tells you that the C: disk contains a folder named Music; within this folder lies a sub-folder named Big-band; and within that folder is the file in-the-mood.mpg.

Some people prefer to read pathnames from right to left. In this case, you could say that the file named in-the-mood.mpg lies in the Big-band folder, which lies in the Music folder, which is on the C: disk.

When it comes to folder and file names, Windows does not distinguish between UPPER CASE (capital letters) and LOWER CASE (small letters). For example, as far as Windows is concerned, the following three pathnames are equivalent:


If you are at all obsessive, you will want to impose a system of your own for using upper and lower case letters when you create files and folders. On my computer, I use all lower case for file names, and a single upper case letter followed by lower case for folder names. For example, I would write the previous pathname as:


This works well for me, and you may want to adopt the same convention for yourself.

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Windows Explorer

WINDOWS EXPLORER is the name of the program that you use to organize how data is stored on your computer. You can use Windows Explorer to move, copy, rename, delete and create files and folders.

Windows Explorer is built into Windows. To start the program, click on the Start button, select Programs, and then click on Windows Explorer.

You may not be aware of it, but Windows Explorer and Internet Explorer are linked to one another. For instance, you can type a URL into Windows Explorer and it will show you a Web page. Or you can type a folder address into Internet Explorer and it will show you the contents of that folder.

Why is this the case? Because Microsoft made a strategic decision some time ago to integrate Windows with the Internet. Toward this end, they tied together Windows Explorer and Internet Explorer. The idea is that the Windows/Internet Explorer hybrid should allow you to look at whatever information you need — on your hard disk, on your network, or on the Internet — using a simple, consistent interface.

As a result of this forced marriage, both Windows Explorer and Internet Explorer are large, unwieldy, awkward programs that are difficult to learn and particularly unenjoyable to use. (Well-designed programs are fun to use.) I can tell you now that there will be times, as you use Windows Explorer, when you will find yourself performing mindless repetitive actions. There will also be times when you will want to perform a conceptually simple operation, and it will take you a great many mouse clicks or keystrokes. At such times, remember that all smart people dislike Windows Explorer. Put simply, it sucks.

If you have only used Windows, you have never really experienced what it is like to use a well-designed computer system, suitable for smart people.

I realize that, unless you have experience with different types of computer systems, you may have trouble appreciating my observations. If you have only used Windows (or a Macintosh, for that matter), you have never really experienced what it is like to use a well-designed computer system, suitable for smart people.

I mention all this because, for better or for worse, Windows Explorer is a crucial program, and you do need to learn how to use it well. Even if you use your computer only to access the Internet, you will find it valuable to be able to look at your files and folders, and to manipulate them as you see fit. Having these skills are crucial if you want to have control over your working environment.

I wish I could show you, in detail, how to use Windows Explorer. Unfortunately, learning how to use the program — especially learning how to use it well — is a problem. The built-in help is confusing and incomplete, and there is no simple way to teach yourself the details.

To help you, I have five general hints. First, if you know someone who is very good at Windows, ask him or her to teach you how to use Windows Explorer, even if you have to use a bribe. (A good bribe would be a copy of one of my books.)

Second, spend some time experimenting with the program. Pull down each menu and examine all the items. Try different things and see what happens. Practice using the short-cut keys and it won't be long until you memorize them. Eventually, you'll figure out how to use the program well. Once you do, teach someone else. (Teaching another person is the best way to really understand the details.)

The next hint is important when you are deleting. To delete one or more files or folders, start by using your mouse to select the items you want to delete. You now have three choices, and they all have the same effect. Either press the Delete key, or pull down the File menu and select Delete, or right-click on the items and select Delete from the pop-up menu.

You might think that when you delete a file it is gone for good, but that is not the case. When you delete a file, it only seems to vanish. It really goes to a special folder with the silly name of RECYCLE BIN. At any time, you can open your Recycle Bin, and examine any of your previously "deleted" files or folders. If you want, you can even restore a file, or folder to its original location. (To do so, select the item, pull down the File menu and select Restore.)

(At this point, you might want to take a moment to relate this system to your own existence. The philosophical implications are profound.)

The Recycle Bin is handy when you have changed your mind about deleting an item and you want it back. If you delete files a lot, you will eventually be glad there is a Recycle Bin to give you a second chance. However, the Recycle Bin is also a threat to your privacy, because anyone with access to your computer can examine any of the files you think you have deleted.

So, how do you get rid of a file or folder permanently? After you delete it from its original location, you must go to the Recycle Bin and delete it again. Be careful, though. Once you delete an item from the Recycle Bin, the item is gone for good and there is no way to get it back. If you want to delete the entire contents of the Recycle Bin, there is an easy way. Open it, and then pull down the File menu and select Empty Recycle Bin.

As you might imagine, it is a bother to have to delete something twice just to get rid of it permanently, so here is a shortcut that very few people know about. First select the files or folders you want to delete, then hold down the Shift key as you perform the deletion. This causes the items to be deleted without being sent to the Recycle Bin.

The fourth Windows Explorer hint has to do with the right-mouse button. Within Windows Explorer — and all Microsoft programs, for that matter — you can perform various actions by clicking the right mouse button. Doing so will bring up a list of actions that are appropriate to the context in which you are working, and you can then select the action you want. If you right-click on a file name, for example, you will get a completely different menu than if you right-click on an empty area of the window. Try it and see for yourself; then experiment.

The last hint applies when you are moving or copying files from one folder or disk to another. In such cases, it is often helpful to start two copies of Windows Explorer. Use one to show you the source folder, and another to show you the destination folder. It is then a simple matter to select one or more files from the source folder and then drag them to the destination folder. (To select a file, click on it. To select several files, hold down the Ctrl key and click on each file in turn.) To drag a selection, hold down either the left or right mouse button and move the mouse.

If you hold down the left mouse button as you drag one or more files, there are two possibilities. If the source and destination folders are on the same disk, Windows Explorer will move the files. If the source and destination folders are on different disks, Windows Explorer will copy the files. (Experiment and you will see what I mean.)

For more control, hold down the right mouse button as you drag a selection. When you are finished dragging, Windows Explorer will give you a choice: you can either move, copy or create a shortcut.

A SHORTCUT is something that points to a file, but is not the actual file. Creating a shortcut allows you to access a file from more than one location. For example, close or minimize all the windows that are currently open on your computer. What you are now looking at, the background, is called your DESKTOP. Notice that your desktop contains some ICONS (small pictures). These are all shortcuts. If you double-click on an icon, Windows will start the program or open the file that is associated with that shortcut.

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Windows Explorer Options

My final advice about Windows Explorer has to do with adjusting your working environment. Within the program, it is possible to set certain preferences. Here are instructions for setting these options in a way that is suitable for a smart person. By default, Microsoft sets them so as to be appropriate for a stupid person. (I'm not kidding. They do it on purpose.)

The following instructions might be a bit different on your computer, depending on what version of Windows you are using. However, the general ideas will be the same, and it won't be hard to figure out what to do.

To start, pull down the View menu and select Details.

Then pull down the View menu (on some systems, the Tools menu) again and select Folder Options. This will open up a new window, named Folder Options, that will have three pages: General, View and File Types. Start on the General page.

Under Windows Desktop Update, click on Custom. Then click on the Settings button. This will open a new window named "Custom Settings". Select the following options:

  • Use Windows classic desktop
  • Open each folder in its own window
  • (View Web content) Only for folders where I select "as Web Page"
  • Double-click to open an item

Hint: When you get really good at Windows Explorer, try changing this last option to "Single-click".

Click the OK button to close the Window. You will now return to the Folders Options Window.

Click on the View tab to bring up the View page. Under Folder Views, click on "Like Current Folder". The program will ask you to confirm your choice. Click on Yes.

Now look under "Advanced settings", where you will see a number of options that you can turn off and on. You won't be able to see all of them at once, but you can pull down the bar to the right in order to view the bottom part of the list.

Under the "Files and Folders" heading, make sure the following options are turned on:

  • Display the full path in title bar
  • Hidden files: Show all files
  • Show file attributes in Detail View

Now make sure the following options are turned off:

  • Hide file extensions for known file types
  • Remember each folder's view settings

Next, under the "Visual Settings" heading, make sure the following options are turned on:

  • Show window contents while dragging
  • Smooth edges of screen fonts

To finish, click on the Close button to close the window.

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Flushing the Cache

As I explained earlier in the chapter, the cache is a special folder where your browser keeps a copy of all the files that it has downloaded from the Net on your behalf. This includes all the content of the Web pages you have looked at, including all the pictures. The cache is actually a folder with the name Temporary Internet Files. To maintain your privacy, you need to empty your cache. When you do this, we say you flush the cache.

To flush your cache, pull down the Tools menu and select Internet Options. This will open a new window, and within this window, you will be looking at the General page. To flush your cache, click on the Delete Files button in the Temporary Internet Files section. As soon as you do this, Internet Explorer will delete all the files in your cache.

Although flushing your cache is simple, it is a bother. If you are very concerned about your privacy, you will have to remember to flush the cache every time you finish using your browser. However, there is a way to have this happen automatically.

Pull down the Tools menu and select Internet Options. Now click on the Advanced tab. Within the Settings box, scroll down to the section named Security. Within this section, turn on the option "Empty Temporary Internet Files folder when browser is closed". Then press the OK button to close the window. From now on, every time you close your browser, the contents of your cache will vanish automatically, like the last breath of dew on the petals of a field of daisies as the sun rises in the early morning.

Remember, however, you are not fully protected. You must still empty your browser history, and that can't be done as easily. You will have to do that manually. (See the instructions earlier in the chapter.)

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