I suggest uninstalling Vista and installing Windows XP with Service Pack 2. You don't have to do that but Vista is crap until they release the SP for it. Well I would say reinstall Graphics drivers and make sure your specs keep up with your card.
You are about to answer a thread that has been inactive for more than 6 months. If you still wish to proceed, please ensure that your posting is original and does not duplicate or overlap any prior responses to this thread.