Unfortunately, it's quite tricky diagnosing what causes intermittent BSODing, as they can be caused by faulty hardware (failing graphics card, PSU, HDD, etc.), malware, device driver, etc.
First thing worth checking is a scan for malware, e.g. using Malware Bytes. This way you can rule this out.
If the BSOD'ing only started happening recently, try running System Restore to a date before you first started experiencing the BSOD. When you do this, do not allow Windows or any software to auto-update for the first day. If the PC remains stable, then apply the updates one by one (or 4 updates at a time if many) and seeing how stable the PC remains each day until you find the culprit. If the PC still BSOD's after a system restore, but before applying any windows/software updates, then it's very likely a hardware problem (e.g. PSU, motherboard, etc.)
Another option is to try the Windows Debugging tools (guide). This is quite a technical task, but it helps identify a faulty device driver if it is a driver causing the issue. Basically, if you see the same .sys file showing up for several crash dump analysis, then do a Google on the file to see what driver is the culprit. I've seen cases of a faulty network driver, ISDN driver, etc. triggering the BSODs where changing to a newer or older driver solved the issue.
If you are able to get by without using the PC for a few days, try creating a BartPE or VistaPE CD and boot it and open Notepad. Leave the PC idle for few days to see if this BSODs, i.e. where you see it back at the start screen without Notepad open. If this live OS BSOD's or unexpectedly reboots, then you've a hardware problem.