Yeah, Windows 7.
The closest I came to finding a possible source with regard to video drivers was a number of posts/solutions in tech forums about one of the errors I kept seeing, apparently to do with versions 4.01, 4.1, and 4.2 of something associated with ATI's graphics cards and software. I kept getting errors saying those services had shut down due to the necessary files not being found, according to the stuff I found v4.01 is an outdated relic and shouldn't be there or be running any more after updates to the gfx drivers but registry entries don't get deleted when they update (despite doing a full uninstall of old software, apparently) and it remains as a "device" in Device Manager and the people reporting the error were also having numerous BSODs, particularly when running fullscreen apps.
I followed the instructions to remove the relevant references to it but that didn't SEEM to have any effect. Of course that was before I started updating/reverting the GPU software in its entirety trying to see if there was ANY version, at all, that would make the problem go away - assuming gfx drivers were the cause of it.
Then I started getting notices about a possible Java exploit being found and deleted, and uninstalled/updated/reinstalled Java just because I didn't know what that might have to do with anything, then I ran virus and malware scans and found nothing, then I noticed Steam wouldn't launch at all, then that problem got resolved and since then everything's fine.
So, to recap, I had a problem and now it's gone and I don't know why I had it or why it went away.
