Whole screen disappears on windows xp!!?

ok, when i turn on my computer it boot up as normal. when it gets to the desktop, it all loads then all of the sudden, all of the icons disappear and it only shows the background, then reappears, then disappears forever. i have to run everything from task manager. system restore doesnt work and i dont need you to tell me to get a new computer or whatever. PLEASE HELP