Go into your advanced system settings and then go to Startup and Recovery Settings, uncheck the option for "Automatically Restart" on the System Failure. The next time the system has a BSOD, write down the error (just the top half and the error code at the bottom should be fine). Also, what kind of Antivirus? Can you boot it into safe mode? If so, run a Malware Bytes scan (download & install from Safe Mode if needed, just pick "Safe Mode with Networking" on startup while tapping the F8 key). It wouldn't hurt to grab SUPERAntiSpyware as well.