Reply #1: One thing ...

[RoyGBiv]

Well, two.

I'm going to let a Windows expert handle this in the main. It's just been too long since I've dealt with troublesome Windows updates.

But, you should disable all anti-malware (virus checker, etc.) when doing a Windows update you are certain is a good one, i.e. one you got from Microsoft itself via the auto-updater or the MS website. That may be what's preventing it from installing. Some of them do that.

I'm taking a wild guess here, but you may have something running that's got the .NET framework in use at the time you're trying to do the update. Turn off everything before you try it.