I had my HDD dead and finally today I got a replacement... So, my PC was not running for 10 days. I have XFX Alpha Dog 8800GT 512MB I installed Vista Ultimate 64bit SP1, and then I tried to install 178.13 geforce vista64bit drivers, and it took a very looong time so I ended the installation, restarted my PC and when it got into Windows, the display just went off, though PC was working. I restarted it in Safe Mode, deleted the drivers and installed older ones, delivered on the XFX driver CD and when I booted Windows again, the same thing happened... Then I went to safe mode, uninstalled drivers and deleted driver files from windows\system32\drivers, restarted computer and booted Vista normally, but it recognized Standard VGA Adapter. I reinstalled XFX driver again and during the boot, I pressed F8 and choose the option of logged boot, and after it booted, the screen went blank again but then the picture got back in VGA resolution, and I changed it back to my native resolution... I ran few benchmarks and the card works as it should, but I'm afraid to turn off my computer again, not knowing will I be able to boot it again... What could be wrong? Is it up to drivers, card, system?