In the early days of PCs, users ran programs directly from diskettes or installed them using simple copy utilities. However, as Windows became more and more complex, companies discovered that some program files conflicted with the core operating system or other programs. To ensure maximum compatibility with Windows, Microsoft developed a program to help software vendors coordinate their efforts with Windows developers. The resulting programs are compatible and designed to work with Windows.

One facet of this program requires companies to integrate utilities with their products that help install, operate, and remove the programs as cleanly as possible. Additionally, developers of Windows-compatible programs incorporate information about the software into their Registry entries. (The Registry is a file that contains system settings and other important information about the OS and its components.) With Windows 95, Microsoft released a Control Panel utility, Add/Remove Programs, that takes this provided Registry information and uses it to create a centralized interface for program installation and removal.

With WinXP, this utility (now called Add Or Remove Programs) has evolved even further into a Swiss Army Knife for program management. Using Add Or Remove Programs, users can invoke a program's installer and uninstaller utilities and, in some cases, add or remove elements from a program. They can also modify their Windows installations, search for Windows updates and other important system files, and set the default programs WinXP uses to open certain files.

However, not all programs should be installed or uninstalled using Add Or Remove Programs. See the "One On One" sidebar before you get started using Add Or Remove Programs.

Let Us Introduce You

To open Add Or Remove Programs, select Control Panel from the Start menu and double-click the Add Or Remove Programs icon. You'll see a square display with four buttons running down the left pane. These are Change Or Remove Programs, Add New Programs, Add/Remove Windows Components, and Set Program Access And Defaults.

Change Or Remove Programs. When you select this option, WinXP generates a list of installed Windows-compatible programs. From this list, you can run a program's uninstaller utility (assuming the Registry entry is correct). Additionally, for advanced programs, such as Microsoft Office, that support the feature, you can add or remove individual elements from a program installation.

At the top of the installed programs list is the Show Updates checkbox. If you click it, WinXP will also display Windows updates you have installed on your PC. (WinXP Service Pack 2 appears as a program, not an update, so it displays regardless of whether you select this checkbox.)

Click any item in the list, and WinXP will display information such as the item's usage frequency, installed size, and links to the manufacturer's support information. (This is a handy reference.) If WinXP cannot find the necessary information in the Registry, it will search the Start Menu and Programs folder for items that are a close match. From this information, it will attempt to generate beneficial information that may or may not be accurate.

For each program item, you will also see one or two buttons. If you see a single button marked Change/ Remove, the program does not offer a separate modification feature. Clicking this button will almost always open the uninstaller program or wizard, but occasionally, you may be able to make limited modifications from this button's menu.

If you see two buttons, Change and Remove, the program includes a separate modification feature. However, this modification feature will often be a component of the Setup wizard. Click Change and follow the prompts until you are offered an opportunity to change installed features.

Click Remove and you will start the uninstallation wizard. The behavior of the uninstallation wizard will vary from one program to the next, but you should see at least one prompt to proceed before actual removal begins. In some cases, the program will uninstall quickly and automatically. In other cases, the wizard will warn you of files that you may need to delete manually. Make a note of these files but do not delete them unless you experience problems with your system; they may be used by other programs.

Once you accept whatever prompts a change or whatever removal wizard provides and click Yes or OK, you may not be able to cancel the removal or modification. In fact, doing so could damage your system installation.

Add New Programs. With this second option, you can add new programs to your PC (click the button titled CD Or Floppy), or you can search the Internet for Windows updates and other system elements to install. (Click the Windows Update button.) Selecting the first option will cause WinXP to search your removable drives for an installer program. Clicking the second option will open your browser to the Windows Update site.

If you want to install a program stored somewhere other than a CD or floppy (such as on the hard drive), use the Browse option WinXP provides at the second screen to locate the installer program. This is usually a file called Setup or Install, but it could be named something different. If the program you are installing does not have a Windows-compatible installer program, you may not be able to install it through Add Or Remove Programs. However, ensure it is not a compressed file (one with an extension of .ZIP, .TAR, .GZIP, or .CAB, for example) first. If it is, WinXP may recognize the file after it is uncompressed with a utility such as WinZip.

In addition, before you install new programs or Windows updates, you should backup critical data. (Data loss is rare, but it does occur.) It is also a good idea to disable any virus protection software you are using, as the software may prevent the alteration of system settings and corrupt the installation. However, if the program you are installing came from an unfamiliar source, such as the Internet or an unknown company, scan it for viruses before you disable your virus protection.

Add/Remove Windows Components. This option lets you add or remove optional Windows components using the Windows Component Wizard. These add-ons are not WinXP system files or updates. Rather, they are modules that enhance the functionality of WinXP. When you select this option, the wizard opens in a new window. Currently installed components will have a check in their checkbox; those not currently installed will have an empty checkbox. (To install an item, select its checkbox; to remove an item, uncheck its checkbox.)

The components available for installation will depend upon the installation type you chose at setup. Many of these add-ons are available only to users of WinXP Pro, and several are designed for advanced users with networks. Windows Messenger (an instant messaging service generally only used by enterprises), for example, can expose your computer to intrusion. You should remove it unless you know you use it. However, some, such as Fax Services and MSN Messenger, can be beneficial to novice users.

You can gather more information on any component before you install it by clicking its Details button. Any component with a plus (+) symbol in front of it contains subcomponents; click the symbol, and you can view the subcomponents and their details.

Set Program Access And Defaults. This option, which is available only in WinXP installations running Service Pack 1 or higher, gives you some control over which programs WinXP will use as the default applications and which programs will be available to users for common actions such as Web browsing and media playback.

For all WinXP users, the Set Program Access and Defaults display has three radio button options: Microsoft Windows, Non-Microsoft, and Custom. Select Microsoft Windows, and WinXP will adjust the defaults to give priority to Microsoft programs such as Internet Explorer and Windows Media Player.

Select Non-Microsoft, and WinXP will substitute available non-Microsoft programs, such as Netscape Navigator or MUSICMATCH Jukebox, for Microsoft equivalents. If no non-Microsoft programs are available, WinXP will change the default to Use My Current Web Browser (or other program) and may disable Microsoft programs. (This feature changes based on the Service Packs you have installed.) If the only available programs in some cases are from Microsoft, do not select this option.

The third option, Custom, lets you tweak the settings. It changes the default for all file types to Use My Current Web Browser (or other program) but lets you enable or disable any listed Microsoft or third-party programs. Disabling access removes the program icons or listings from the Start menu, the Desktop, and other places where they commonly appear. To disable any program, deselect the Enable Access To This Program checkbox for the appropriate program.

Unfortunately, WinXP is too selective in its lineup of programs from which you can choose. On our test system, for example, even though we had both the Foxmail and Outlook 2003 email clients installed, neither appeared as options for default selection.

Users of PCs whose manufacturer preset its defaults will see a fourth button: Computer Manufacturer. Select this option to reset the defaults to the manufacturer's specifications.

Up & Running

Add Or Remove Programs is a powerful tool that gives you more control than ever before over the way programs are installed and executed on your PC. In tandem with related installer and uninstaller utilities, it can help keep your system operating at its peak. Spend some time getting to know this utility and see what it can do for you.

by Jennifer Farwell