I would suspect a hardware problem. Software-induced bluescreens are not as often these days as they used to be.
Here is the order I would troubleshoot this:
- Hard drive SMART status (is it failing?);
- Component temperatures (are all the fans running?);
- Power supply voltages and ripple (how old is it? Dry capacitors?);
- RAM test (thorough 12-hour or longer test with Memtest86+).
If a problem is not found, clean OS reinstall with most recent hardware drivers.
As always, your mileage may vary.