Unlocking a console

I would like to know if there is a way to unlock a (L5) console, running on Vista 3, if the person who locked it, is unfindable and the password that he used is unknown.

Send you a private message about unlocking. This would only work on Vista itself, it does not apply to a Windows account password.

@ben.coleman Could you also send this as well to me? I have run very close to this issue before.