Why not start with this article:
http://support.microsoft.com/default...b;en-us;824643
How to troubleshoot Microsoft .NET Framework 1.1 installation issues
"Brian D. Scott" <Brian D.
> wrote in message
news:484E310C-2D1F-449F-A8D4-...
> Windows Update correctly believes that .Net 1.1 should already be installed
> on my WinXP SP2 system and indicated I should install SP1 as critical update.
> It however consistanly fails. I then downloaded the actual patch -
> NDP1.1sp1-KB867460-X86.exe but when I run it, I get the Windows Installer
> message saying the program to be upgraded is missing or the patch is for the
> wrong version. This is a new system and when .Net 1.1 was installed from
> Windows Update, I was having numerous bug checks due to bad RAM dimms.
> Although .Net appears to be installed, there is no entry for it in the Add
> Remove Program menu! I tried temporarily renaming the
> C:\Windows\SoftwareDistribution folder to tick Windows update into believing
> .Net 1.1 wasn't installed but that didn't work. Does anyone know a way around
> this problem as my ATI Catalyst 5.4 driver needs .Net 1.1 as a prerequisite.