I'm not sure what you mean by redownloaded -- reinstalled .NET? Did you install .NET 3.5 or 2.0? 2.0 is part of 3.5, but sometimes if 2.0 had been present but was then removed, that makes it so that it won't work right without 2.0 also being installed. Is the error when you run AI War any different? If that doesn't work, then I'd suggest try installing AI War 3.0 again, as it's possible, though unlikely, that that was what was corrupt. You might also look around in your system event log and see if there are any other errors under the system or application sections. If .NET is messed up, or was unable to install fully, that might be throwing some other errors on windows boot.