This is a weird problem so bare with me. I have several PCs that do this with in the company. I can't find anything different on these PCs than any other. They are running Windows XP Pro SP2 and they are all on the same domain as every other PC. Installed programs are Adobe Reader, Office XP, AS400 emulator, and Officescan client. Randomly when the user logs off, the login screen will change. Instead of asking for Ctrl + Alt and Delete to log on the computer, it will just display a login screen. The username is blank and instead of the domain name it will want to log onto the local computer. Not matter what you try you can not log back into the PC until you restart it. There are no errors created either. It's kind of a hard problem to explain so let me know if you have any questions that would better get my point across.