First of all why the hell are you trying to install IIS in Xp.....???

I am sure you are aware of the fact that IIS is used for web services in windows like apace in Linux (well, you can run apace in windows as well).

You can install IIS if you have to using the following steps:

During installation, IIS installs optional components like Common Files, Documentation, and the Internet Information Services snap-in. You can choose not to install the optional components; however, deselecting specific components can decrease IIS functionality or disable IIS services. If you are unfamiliar with the optional components and how they affect IIS, install IIS with the default settings. After you install IIS, you can view Installing IIS Optional Components in the IIS online documentation for more information.

To install IIS, add optional components, or remove optional components

1.Click Start, click Control Panel, and click Add or Remove Programs.

2.Click Add/Remove Windows Components. The Windows Components Wizard appears.

3.Follow the on-screen instructions to install, remove, or add components to IIS.