Win2K Pro Bootup Freezes

When booting up a Win2K Pro PC, before it gets to the network login screen, it stops at the “Applying Security Policies” screen. You cannot ctrl/alt/del to reboot it. You have to push the reset button. We had a scanner malfunction, and it asked to reboot the PC. We did not reboot, we shut it down properly and then turned it back on. How do I get the PC to boot up all the way? And, why did this happen? Thank you!