Net Framework Update Trouble

[Georgexp]

Originally I received error 0x643 while attempting to install KB951847. I
followed instructions of kb923100 and unstinstalled all versions and checked
with cleanup tool that they are gone.
I downloaded all offered sources. I installed versions 1.0 and 1.1 without
problems but the installtion of version 2.0 fails: Setup cannot continue
because this version of the .NET Framework is incompatible with a previously
installed one. For more information, see
support.microsoft.com/support/kb/articles/q312/5/00.asp

That reference doesn't help.

 

[Georgexp]

The environment is XP Professional (version 2002) with SP3.