|Depends or reasons. For most people the software is borked. Reload it using the owners manual, usually termed a recovery or some such term. It returns it to as bought state.|
It could still be any number of hardware issues but I'd try the reload. Might boot to the vista dvd and use the memory diagnostics just to be sure.
1/3 of highway deaths are caused by drunks. The rest are by people who can't drive any better than a drunk.