"Unlock Computer" Screen Keeps Popping Up

Yesterday, out of the blue, a screen started popping up every few minutes titled, "Unlock Computer." It It reads, "This computer is in use and has been locked. Only (my name) or an administrator can unlock this computer." My name appears in the Username box, and the Password box is blank. If I just click on OK, everythinggoes back to normal, until that screen appears again in a few minutes.

I'm the sole user of this PC, and have never had to log into it. I don't think I ever even had a password.

Can anyone suggest a way to prevent this screen from showing up? And, does anyone know why it's suddenly appearing?

EDIT: Also, I just tried to update my profile/signature (system specs), and got a message that I "don't have permission to use simple HTML." Is this something new on the forums? (I haven't been here in a while.) How can I get this "permission?"

Thanks,

Richard

Message Edited by vetriguy on 12-13-2004 01:36 PM