I've been having a number of wonky problems recently that all seem to point to my GTX 460, but I want to make sure there isn't another (or more systemic) problem afoot. First, here are my specs. All components are currently at stock, though were overclocked in past for temporary performance boosts during heavy use (e.g. gaming, video editing).
Two optical drives
One internal HDD, two partitions (one boot, one for files)
Windows 7 x64
The Problem: A few days ago, I started sporadically encountering "NVIDIA Windows Kernel Mode Driver Version xxx.xx has stopped working" errors, similar to this link. This happened occasionally when using Firefox and frequently when starting up games (note: hardware acceleration was enabled in Firefox). However, I could boot up and do basic tasks.
I tested the drivers and my boot drive extensively. I performed a clean install of the previous drivers, even using DriverSweeper and other tools to annihilate all traces of 320.18. That didn't work, so I did a system restore. No luck. I made a back-up drive image and restored a previous image backup. Still getting errors. When I ran 3dMark06, I got "IDirect3DDevice9: resent failed: Device lost (D3DERR_DEVICELOST)" consistently on the first test.
I don't have any other spare components around, so I went to a local tech shop to test another GPU. It worked fine, so I figure it might be my card. I couldn't test my card in another system, however. Then I go back home and reinstall my GPU temporarily. Lo and behold, the next morning I can run 3dMark and play games. It's working. I even restore my most recent drive image; everything still okay.
But, problems have re-materialized, though not as dramatically. First I saw mouse cursor corruption (my mouse icon can turn into a pixelated rainbow icon or get stuck on the text insertion cursor). I start to get streaking and lines in Bioshock Infinite occasionally. My system freezes for a few seconds occasionally. I can still play games and such, but something is definitely wrong.
Is this an obvious GPU problem? I would like to rule out possible PSU or motherboard problems (or something else I can't think of). Prime95 has tested the CPU and RAM moderately, which seem to be alright. I plan to do more intensive Prime95 tests and conduct some FurMark trials. But because my system can apparently handle some load, I'm not sure how to best test and eliminate possible problems.
Anyhow, sorry for the wall of text. I appreciate any advice you all can offer.
P.S. I dusted my system with compressed gas, installed Crysis 3, and updated the Nvidia driver around the time this all started. I do not know if it is connected at all.