Hi baggi,

during the day as i was working on it, one of the kids pulled out the plug of the computer, shutting it down.
I guess that means that it hasn't saved your previous settings and has gone to some sort of default? Basically, Windows saves your settings after each session, so it is particularly important to shut down properly with your first session after installation.

You might try:

Control Panel
Administrative Tools
Local Security Policy
Password Policy

And change the minimum password length to 0.

You may have to recreate your user accounts without passwords.