Forgotten computer password

[netibiza]

My friend who is even more ignorant of computers that ! am, has forgotten his password and can't get into his computer. He has Windows Vista. He normally leaves it on 24/7 but due to a power cut, it went off, any ideas as to how he can bypass the password. He has asked a computer company in town but they say they also need to know the password!! Believe me this is genuine, we are not hackers!!