Just out of curiosity, but for those having the issue, do you have UAC turned on or off?In any case, this issue is just one of those things that nobody can seem to find "the" solution to, or "the" cause for. I've seen people fix or sort of fix it by replacing the card, changing the motherboard, sometimes with a different brand, upping or decreasing the PCIE bus speed, changing their ram or ram timings, using a specific driver set, using a different chipset driver, finding out that Vista installed an older nvlddmkm.sys file, and by replacing it with the one in the driver set they installed fixed the issue, and so on, and so on. All sorts of fixes, but not one definitive "this is the problem" answer, or "this is how you fix it" answer. The oddest thing is that the situation is all over the place. It can occur during install, after install, Vista can work fine for weeks then all of a sudden BSOD with this error, it can happen when running an SLI setup or single card, and it can happen when playing games to watching DVDs, or even running Vista Aero can cause it. AND I've seen reports of it happening on ATI systems too, sometimes tied with the nvlddmkm.sys file which doesn't make any sense unless it was left there from that person switching to ATI from Nvidia, but more often than not the atikmdag.sys file will be the culprit.At one point I remember Microsoft admitting it was their fault, something about it being related to DirectX 10 code or some such, and it was 2 months later that a couple graphic hotfixes came out for Vista. Unfortunately the issue still occurs.