Wont pass windows xp screen

Hey guys im having some problems with my laptop at the moment, it seemed to be fine the other day, i dont know if anyone has been messing with the settings on it but i turned it on today and the screen has gone all weird, it seems to look like its been moved to the right, the windows xp logos have changes colours but in patches and i cant read anything on the f8 screen as every word is missing a few letters and the black screen behind the writing will flash green with stripes on it if any button is pressed and also it will not pass the windows xp screen on startup after that its just black, it dosent turn off it just stays black. :S does anyone have any suggestions ? thanks