hi ive been having problems with my computer every time i load a web page to a streaming video like you tube the bottom 3rd of my screen flickers just once i don't think its my monitor as i have 2 and it does it on both when it does it i'm thinking it may be my gfx card but the computer is not that old less than 2 years its a dell xps 8100 the card is an ati hd 5770 does anyon know any programs that can detect gfx card problems ?