XPS 1710 loading windows vista problem

Whenever i start up my computer, the dell logo screen is coverd with little dots, and it briefly goes to a screen of a's with little accent marks on them. if i start windows normally it goes to the loading windows bar, then cuts to black. if i put it on safe mode it has a black background with blue squares on the background. And if i try and debug or check to see if there is a problem it says its fine, and i was given the blue stop screen twice in the last month for an optial error, i just dont know how to check whats wrong, let alone fix it.