MrRT
Because you received the IBM Thinkpad computer from your mother's work, it is password protected by the company. if your mother has the password to get into the BIOS [inside the computer itself] and after that the windows program you are alright. GOTO the IBM thinkpad web site with the model number and they can show you how to disable the BIOS password so that you can get into Windows without too much problem.
next, You have to sigh on Windows xp, Vista as an adminisrator and set your self as an administrator. Set up YOUR name as a person that does not have to " sign In" and every time windows starts, you can get in without signing in.