Cypher17

Everytime I try to open a game or something requiring .NET Framework I get this error message:

To run this application you need to install one of the following applications:

.NET Framework v2.0.50727

I already installed this, and it errored, and it did not appear on my add/remove so I couldn't uninstall it. So I tried deleting it manually through the Framework folder, which Vista won't allow me permission to do. So i did the next best thing and ripped it out onto my desktop. I tried to reinstall and the installer claims that 2.0.5 is already installed, and I can't even reinstall 1.0 or 1.1 because it errors, and I can't install 3.5 because it thinks there's a prior version. So now i'm stuck with three folders on my desktop I can't delete, no .NET Framework and seemingly no way of getting it. What do I do?