Quote:
1. Click Start, and then click Run.
2. In the Open box, type control userpasswords2, and then click OK.
# Clear the "Users must enter a user name and password to use this computer" check box, and then click Apply.
# In the Automatically Log On window, type the password (Blank) in the Password box, and then retype the password (Blank) in the Confirm Password box.
# Click OK to close the Automatically Log On window, and then click OK to close the User Accounts window.
Is a place to start, if happens again, will try to find a better solution for you