.NET screwed up in vista

hey, yesterday I tried to work on my program that I've been writing off and on for a week. I launched MS visual studio 2005, tried to load my project and received an error saying that it couldn't open the project. I then tried running the binary that was working last week, and I receive an immediate error. Right away I suspected it was something wrong with the framework, so I ran another program that requires .net, and it failed too. I then ran them on xp and it worked just fine. I ran the system file checker with the /scannow switch, but that didn't fix it. I have all the updates installed for visual studio. I don't know what else it could be.

Any ideas?

i am running vista 64 ultimate edition and i have .net framework installed and it works fine. i don't have a fix for u, but have u installed version 3? when installing v3 it also installs v2. make sure both are installed in add/remove progs.

.net is integrated with vista. It comes with the installation. It was working and then stopped. I thought I could repair it by downloading from MS, but when I tried to install it told me it couldn't install on vista.