Chapter 7: Using Files and Folders

What Are Filenames?

To store a file and retrieve it later, Windows has to give it a filename. Often you are asked to invent a name for a file. Good filenames are evocative without being too cumbersome. They also have to conform to some rules. Fortunately, the file-naming rules were liberalized when Windows 95 came out, and Windows XP retains these liberalized rules. You can change a filename using Windows Explorer, as well as in the Open and Save As dialog boxes of many applications.

What Filenames Are Legal?

In DOS and Windows systems prior to Windows 95, filenames could be only eight characters long, followed by a three-character extension that told the file's type--Filename.txt, for example. Inventing coherent, easily remembered filenames was an art similar to composing good vanity license plates. Even so, one frequently had to stare at files like jnsdecr.doc for some time before remembering it was John's December report.

Fortunately, Windows 95 changed all that by introducing long filenames, and Windows XP retains that advance. File and folder names can be up to 215 characters long, and can include spaces. So jnsdecr.doc can become John's December Report.doc.

Folders, likewise, can have names up to 215 characters long. These names are automatically of type "folder" and have no extension.

In addition to periods and spaces, some characters that were illegal for file and folder names prior to Windows 95 are now legal, including

+ , ; = [ ]

Still, there are some characters you can't use in filenames, including

\ / : * ? " &la; &ra; |

and any character you make by using the CTRL key.

What Are Extensions and File Types?

Filenames are still followed by a period and an extension, which is usually three letters long. The extension denotes the file type and, among other things, tells Windows which program to use to open the file and which icon to use to represent the file. Windows handles most file-type issues invisibly. Files you create with a particular program are typically given a type associated with that program (unless you specify otherwise), and the appropriate extension is added to the name automatically. For example, Web pages usually have the extension .htm or .html, and text files usually have the extension .txt.

You can do many things in Windows without paying any attention to file types; therefore, Windows doesn't even show you the extensions unless you ask to see them. We recommend you configure Windows to display extensions for two reasons: to help you know the complete names of your files and to help you determine the types of files you receive from others. To see the extensions:

1. Choose Start | Control Panel. You see the Control Panel window.
2. Select the Appearance And Themes category, and then click the Folder Options icon. The Folder Options dialog box appears. You can also display this dialogue box by choosing Tools | Options from any Explorer window.
3. Click the View tab. The Advanced Settings box contains a long list of options.
4. Click the check box next to Hide File Extensions For Known File Types. If the box is checked, the extensions are hidden; if it's not checked, the extensions are shown.
5. Click OK to make the Folder Options dialog box go away, and close the Control Panel.

When you install a program, the installation program usually tells Windows the file types the program handles.

What Are Addresses?

An address is information that tells you (and Windows) how to find something. The four kinds of addresses are:

• File addresses Tell you how to find files on your computer. A typical file address looks something like C:\Windows\Explorer.exe.
• UNC (Universal Naming Convention) addresses Used when referring to files on some local area networks (LANs). UNC addresses are in the format \\computername\drive\pathname, where computername is the computer's name on the LAN, drive is the disk drive on that computer, and pathname is the file address on that drive. For example, if you needed to open a file called Budget03.xls in the C:\My Documents folder on a computer named DebB, you'd open \\DebB\C\My Documents\Budget03.xls.
• Internet addresses More properly called URLs, specify how to find things on the Web. The URL of Microsoft's home page, for example, is http://www.microsoft.com.
• E-mail addresses Tell you how to find the e-mail boxes of the people to whom you want to write. You can comment on this book, for example, by writing to winxptcr@gurus.com.

The Address box in Windows Explorer handles every kind of address except e-mail addresses. Typing a file address into the Address box opens the corresponding file or folder on your computer, typing a UNC address opens the corresponding file or folder on your local area network (if your computer and the computer that has the file or folder are logged into the LAN and you have permission to open it), and typing a URL opens the corresponding Web page on the Internet (if your computer is online).

Note: E-mail addresses are still handled differently from the other kinds of addresses. You can send e-mail by typing mailto: followed (with no space) by an e-mail address into the Address box windows runs your e-mail program and starts a message to that address (see Chapter 23).

File addresses, also called paths or pathnames, work in the following way: files and folders are stored on disks. Each disk drive has a drive letter that is its address. Drives A and B typically are reserved for floppy drives, and C denotes your computer's main hard drive. Subsequent letters are used for other hard drives, CD-ROMs, tape drives, removable drives, drives on other computers on your LAN (if any), and other devices. In file addresses, drive letters are always followed by a colon (:).

Each file or folder address begins with the letter of the drive on which the file or folder is stored. The root folder--the main, or top-level, folder on the disk--is designated by a backslash immediately after the drive letter and colon. (So C:\ is the root folder of drive C.) The rest of the address consists of the names of the folders on the folder tree between the given file or folder and the drive that contains it. The folder names are separated by backslashes (\).

For example, the address C:\Windows\Temp refers to a folder named Temp, inside the folder named Windows, which is stored on the C drive. If the file Junk.doc is contained in Temp, Junk.doc's address is C:\Windows\Temp\Junk.doc.

Both file addresses and UNC addresses use backslashes (\) to separate the pieces of the address. But URLs (for historical reasons) use slashes (/) for the same purpose.