lol was just a thought coz with nvidia cards the nview manager can control window positions independantly of the windows os. the link above to the registry "hack" seems pretty good but be careful in there it can get nasty. ALWAYS make a backup before tweaking. open regedit and follow the microsoft link to the reg entries which should look kinda like the ones i attached below. good luck
might be worth running some spyware removal tools on it as well. changes in the registry that arn't expected can be a small pointer to proggys that aint supposed to be there!!