change a password

For best results post this thread in the technical area of the site and inform what operating system and what part of logging in does the request come from at boot up, at profile, etc..? I'm not trying to be sarcastic or mean just trying to assist to help focus the problem to get the best help. I trust that you are using XP? Or is it a CMOS password? Can youo contact the person you bought it off of to verify the correct password? There are some tools depending what operating system or clearing the cmos battery by removing it or readjusinting the jumpers.