Windows not installing right

I used boot camp to make my partition to install windows 7. It installs fine and after finishing installation when it loads the desktop its fine. However when it restarts all I get is a black screen with a blinking underscore _

I tried partitioning the drive myself too and even tried using rEFit. I am at a loss as to what to do. I've had it installed on here before so I don't know what is wrong. Any help would be MUCH appreciated.

Thanks!

I installed it on VM Fusion just fine. No problems whats-so-ever. then i tried again to install it to my hard drive same problem and when i used rEFit partition tool to sync the MBR's it just gets stuck at the windows diamond. I really need help with this guys.