Since it is happening that often, start the PC up in SAFE MODE a quite a few times... you will have limited functionality, but try to leave it like that and use it to generate a BSOD.
If you can't get the BSOD, then its DEFINITELY a driver that is causing the issue.
you can go to RUN then type in MSCONFIG. Then hit the STARTUP tab. Have a look through here for suspicious items.... or even better, if you hit the GENRAL TAB, and select "SELECTIVE STARTUP" and untick "LOAD STARTUP ITEMS".
Now start using your PC in normal mode - again your functionality will be limited, but you can then see if it crashes.
If it doesn't crash (hopefully) go to that STARTUP tab again, and add ONE item. Reboot, and try again. Keep repeating this process until you crash out... The last item you ticked before the crash is your culprit!
HTH