yesterday when i installed the drivers of my new graphic card radeon hd 5770 windows 7 didn't work after bootup, instead of the welcomscreen i get a blackscreen and then i goes to a empty desktop (no icons, no startbutten, etc..). no programs will start not even taskmanager. windows repair finds no problem and the only way to solve it is to bootup in save mode and uninstall the video card. i've tried the drivers from the cd and those on the site. i use windows 7 64bit and i have a 550w powersupply. i hope someone can help me