I decided to format my hdd due to many, many viruses and installed WINDOWS 7 ULTIMATE 64-BIT (previously: WINDOWS VISTA 64BIT). After installing SP1 I tried to install the newest drivers for my graphic card (AMD HD5770).
Before I deinstalled all drivers required to avoid complications. However, in the middle of the installation process, a reproduceable BSOD appeared.
It also did not work to manually install it from the downloaded data, and now I'm pretty helpless