But when .NET Framework updates/reinstallation failes, be sure to:

1. Check to determine if/what processes are holding onto (locking) the .NET assemblies in the GAC. These processes should never be holding onto the GAC assemblies anyway, this is a no-no.
2. Terminate the processes found.
3. Determine the software that initiated those processes, see if you can prevent them from starting up automatically.
4. Contact the software company and tell them that their processes should not be locking up assemblies in the GAC.

Interesting. You can also see archived listings – what did they think that apartment was worth 3 months ago.