How to unlock a Win2K3 virtual machine

Hi,

I have a Win 2003 Server virtual machine set up on my VMWare server. It seems to have locked up after a system reboot. I can access it through the VMWare console, but I get the message that the computer is "in use and has been locked". I send Ctl-Alt-Del, and I get a login dialog, but I can't fill it in. In fact, the VM seems totally unresponsive to any console commands.

Any ideas?

Thanks,

Mike