Ok read this carefully;
1. Look to see what version of windows 7 or vista or xp you are using. the version you used when your pc got blue screen butt fucked
2. Keep that handy
3. Go buy windows 7. If you already have it buy a different version of win7, like win7 ULTIMATE, or vista premium, or xp
4. then install the new version of windows you got.
5. Should work