Are you getting windows 7 update error 80080005? I wasted a lot of time chasing this one as this error code is common to Vista and other problems.
Here's a quick fix. The problem is that you probably loaded a lot of 'stuff' and your registry is full. This is what you need to do (under an administrator account):
- Open your registry editor
- Go to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control
- Edit the RegistrySizeLimit key
- Set the value to 4294967295 in decimal pr ffffff in hex
After this windows update should run fine. Let me know if this helped you or post a quesiton.