Edit: Something important I keep neglecting to say, use Safe Mode
Also, when exactly does it BSOD? On system boot up, or after you've used the PC for a while?
1. BSOD usually shows you the problem, did you manage to see any code or message, if you did which one. If you didn't manage to do that, or the BSOD didn't repeat, try #2.
2. Check the Event Viewer, it might have recorded the error.
-Control Panel
-Administrative Tools
-Event Viewer
Once you open it, check for any errors that may have happened around the same time you got the BSOD, errors are red.
Post the details here.
3. Try updating your windows.
4. If update doesn't help, try booting your PC with minimal hardware.
5. A system restore to an earlier point in time may resolve this, but if it's hardware issue, the BSOD will repeat, which is why it's best to determine what caused the BSOD first.