Windows 7 & .NET 4.0 Beta 1
I upgraded to Windows 7 today and failed to Uninstall .NET 4.0 and VS2010 BETA 1. This left me with non working SQL Management Studio (2005 & 2008) with the error “Microsoft SQL Management Studio Package failed to load”
It also screwed up all my Red Gate software and VS2010. Then I found out you should install Windows 7 after removing .NET 4.0 BETA 1 and Visual Studio other wise you will have to flatten your PC and do a fresh install as the .NET Framework is broken and unfixable. Not really true. I found this worked for me.
Remove .NET 4.0 BETA 1
For x86 OS:
cmd /c "msiexec /x {19BD09BF-3BBD-3663-A5ED-50B6B2B07E42} /qb"
cmd /c "msiexec /x {1DF6A8F6-5048-323F-8758-DA533CE0F07E} /qb"
For x64 OS:
cmd /c "msiexec /x {175D5555-EE49-3033-99AF-BC1E206223FD} /qb"
cmd /c "msiexec /x {13B27C82-19BA-3494-9420-F932B40673CA} /qb"
Then
- Reboot
- Uninstall Visual Studio 2010 and its redistributables
- Reboot
- Install .NET 4.0
- Reboot
- Install Visual 2010
Links to this :-
Download .NET 4.0 Beta 1
MSDN Forums where I found above info.
Hanselman – Before Upgrading To Windows 7
Now I can wait until I get an SSD drive before I do a clean install 
.