Verified answer

You can use the operating system recovery disc set made for the laptop and install a new fresh copy of windows just like came on it if you got the disc set with the laptop.

You can download this live CD password reset / recovery tool and run the CD then after log in and change the administrator password to one you want to use the remove and delete the other persons files, pictures etc. Ophcrack is a free Windows password cracker based on rainbow tables. It is a very efficient implementation of rainbow tables done by the inventors of the method. It comes with a Graphical User Interface and runs on multiple platforms. http://ophcrack.sourceforge.net/

Older laptops running Windows XP, 98, 95 etc do not have a built in system recovery so you have to use a set or recovery disc or install disc to reinstall the operating system. Post the installed operating system as well as brand and model number when asking a question.

Reinstall the operating system. Did he give you the OS CD? Is their a CD key attached on the bottom of the laptop? If it's obsolete (Windows 2000 or earlier), I'd install Ubuntu on it.

http://www.ubuntu.com/

Upgrading the bios will best repair insects and upload new CPU items to the bios. If you have been to overclock the video card or upload reminiscence chips to it, you might void the assurance of a computer with a constructed in video card.