ok, so i have a custom built computer...running windows 7 ultimate. i have an athlon duel core processor with an ATI Radeaon 4850 video card. I recently had some spyware problems so i did a system recovery....now when i turn my computer on it show the windows logo but right after that the screen goes blank. the only thing i can see is my cursor. What have i done and how can i fix it. i am new to this kind of problem. please help.