I have recently upgraded, adding the GTX 295 and an extra 2x 2GB sticks of RAM. Prior to this upgrade i was fine however now i am seeing quite a few 'Exception code: 0xc0000005' AppCrashes in high-load games. The secondary use of my PC is music production, but my sequencer and plugins are all 32bit. I see perfectly stability in these programs and in Windows in general.
Seeing as the only application error i am seeing is 0xc0000005, i would like to investigate RAM voltage\timings and general voltage issues before i look at other things.
I have recetly upgraded from Vista 64bit to Windows 7 6bit and am seeing exactly the same issue, so i am fairly convinced there is a hardware issue (be it a fault, or misconfiguration).
Could this potentially be a voltage\timing issue? My timings are set to 5-5-5-18 with a DRAM voltage of 2.1, which look to be the spec for my RAM. I have left the NB voltage well alone. Any tips or pointers for diagnopsing this issue woiuld be greatly appreciated.
Did you run memtest for several hours? Do you still experience that error if you go back to 4 GB? What if you go back to the previous video card? Is your PSU up to the task? After all you seem to get the issue only when running games and that could indicate an issue with the PSU or the GPU.