Try unplugging all your external and internal drives and devices except for your CPU, GPU, Ram, and boot drive, of course. If you can run in that configuration without problems, then you will know that the problem lies with one (or more of your devices other than CPU, GPU, or ram.) Conversely, if you still have the problem, then you know where it's located. Plug/connect each device back in, one by one, and test the system as you add in each drive or device. If you connect a device and you begin having problems, you've narrowed it down to the specific device--where it could either be a driver problem or a device hardware problem. I once had a situation years ago where I kept getting BSODs that referenced my GPU driver, and after I had satisfied myself that the GPU driver was fine, I followed the advice I just gave you--and lo and behold--I discovered I had an onboard HDD that was failing--not failed yet--but failing, and after disconnecting that hard drive, the system was fine--never had the problem again...;) Plug it back in--BSOD's--and it wasn't even my boot drive! bizarre--and I don't know where the GPU error came from. One other time I found I had a single bad chip on a ram DIMM--that I didn't catch early because I didn't let the memtest run overnight--shut it off after a couple of hours thinking that was good enough--it wasn't.
The only other thing that fits your description is a failing or else weak PSU--it's a common cause of system instability, actually, especially when people build new systems but drag along some components from their previous system--such as the PSU. I would probably check out your PSU first--I prefer a single-12v-rail, myself, of at least 62amps on the 12v rail. But if your PSU is fine, you think, then let the testing begin!...;)
