Vista Locks UP

I just purchased a Dell XPS 630. It continues to lock up. It will do this no matter what situation the computer is in. It will do it in idle, playing games. Doest matter. I have to hard shutdown the PC to get is back up. When the computer is booting, I only get a Windows did not shut down properly. When the OS comes up, it does not show any error logs or prompts to why it froze. How can i tell what is causing this?