sudokusolver 0 Newbie Poster

help please im at my wits end on how to solve this problem i have a compaq pc with winxp sp2 installed in it .everytime i open a new application or try installing some new progs/apps the application window starts but mysteriously disappears after 10-15 secs however it keeps running in background . when i try to terminate the program using task manager it too disappers if im not fast enough. to solve this i have dine following things but didnt succed
1 reinstalled xp - problem still persists
2 already scanned for spywares / viruses
i have a nvidea graphics card with 512 mb ram p-4 processor
my bios isnt upgraded could tht b the reason???????plz help me!!!