I've had a Windows update refuse to install on a couple of machines which are used for software testing. Turns out these machines had Microsoft .Net Framework 2.0 beta1 and Visual J# Redistributable beta1 installed.
Machine #1 was easy, I just went to add/remove programs and removed the beta stuff but machine #2 did not show the beta software to remove.
I found a Microsoft KB article Q320112 but I am always squeamish about manually deleting stuff from the registry so I did it a slightly different way.
Then I used the installer cache to uninstall J#
- Start > Run > Installer
- Right Click Date Modified
- Select Comments
- Click Comments
- Scroll down to find Visual J# Beta
- Right click and uninstall
Then I installed it from the downloaded file
Then I uninstalled it from add/remove programs.
Repeat for Microsoft .NET Framework 2.0 beta1.
Finally I manually installed Microsoft .Net Framework 2.0 from here.