Microsoft Windows 2000 Password Reset!

I was just given a new Computer from my Grandfather, who just passed away. Problem is, Nobody knows or can figure out the password(s), for his logon nor the admin profile. It’s for a Dell Notebook running Windows 2000 Professional. Can anyone help, without having to purchase one of those Password retrieval programs. Unfortunatley I don’t have any of the original Software discs or reboot discs. Any suggestions? Please Help.