I recently reformatted my hard drive to reinstall everything I had. (system was locking up duribng game play). Reseeded video card radeon 9800 pro. As I reboot my computer the bios scrren appears at the top of the screen, but some of the characters are corrupted. When I get to desktop page, there are verticle lines coming down the page. Makes it very difficult to read. I checked add remove programs for the ATI drivers, none. I installed the ATI drivers again( hard to read) , system reboots at the end of installation. System hangs with a black screen with white squares all over the screen. help?