How to Install ASP.NET on Windows XP Pro
- 1). Click the Windows "Start" button. Click "Programs" and then click "Windows Update." This opens the Windows Update utility.
- 2). Click "Check for Updates." The Windows Update utility searches the official Microsoft website for updates for your computer.
- 3). Click the "Install Updates" button. It takes several minutes to download the .NET installation files and install it on your computer.
- 4). Click "Restart" to reboot your computer. After the update installation, you are required to reboot your computer.
Source...