Vista/Performance Issues

Okay, after going to Windows 7 and back to Vista, I have had some performance issues... drivers are up to date, I used my personal x64 Vista disk... defragged, etc... When I start up, I get a "Chiso.dll not found/could not load" error. Can't find chiso.dll on google, either. Could be a virus, but Norton did not find anything. Dawn of War 2 runs pretty poorly, some games will just freeze during play...

So I really don't want to (I'm pretty lazy) but I guess I will have to reinstall Vista once again... after installing Windows 7 about 3 times, getting it all set up, going back to Vista, getting it set up... Is there a best way to do this so that I know I'm going to get the best performance and hopefully not run into many errors? Also, is there anything as good as PeerGuardian, that works well on x64? I had to do a whole bunch to get it to work, then go into cmd on the Windows CD to remove some test logos... rather not do all that again.

I'm not technically challenged (actually quite the opposite) but when I fix other peoples crap all day, the last thing I want to do is fix mine... figured I'd come here and ask.

Thanks,
X

 

reinstall OS.
i had problem with drivers too when i was trying to install too many drivers without restarting. i was keep getting error message, vista score wouldn't work and drivers wouldn't install properly.
i tried uninstall and reinstall stuff and still didn't work. i formatted hdd and reinstalled window and after that, i took my time and restart properly after each driver installation and everything worked fine.
haven't had any error since then.

 

Okay. Any good way to do it? A setup guide or something?