Windows 2003 – Login Screen is Black Except for Logo
So, I had a server that ran out of disk space on the OS partition. Easy to fix, but when I rebooted the server, the screen was black except for the box that has the Windows logo. I was still able to login, but I had to guess at field I was on when typing. Well, it seems this is a strange by-product of not being able to save your profile when logging off.
There is a somewhat simple solution, but it requires a working server.
http://support.microsoft.com/kb/906510


