Repairing the .NET Framework 2.0 and 3.0 on Windows Vista and Windows Server 2008

I had a problem recently with some files from the .NET Framework 2.0 being corrupt. I think the root cause of the problem was use of Virtual Machines. Anyway, I needed to repair the .NET Framework 2.0, specifically aspnet_regiis.exe.

The problem is that under Windows Vista and Windows Server 2008 these components are part of the operating system so you can't do a repair with the MSI like you normally can with installed programs. After doing some digging I found the answer here:

http://blogs.msdn.com/astebner/archive/2007/03/26/how-to-repair-the-net-framework-2-0-and-3-0-on-windows-vista.aspx

The short story is to run "sfc /scannow" with elevated privileges.