|You have to boot the computer into Safe mode, |
(Take any bootable CD or DVDs out of the drives, press F8 repeatedly while booting, do not hold down the key, and choose Safe mode or Safe mode with networking from the boot choices menu)
then log on as Administrator, and if a password is required, you must provide it.
Once you are logged on as Administrator, you can change the priviledges of the other users to be the same as for the administrator.
If there is a password, the relative(s) should know it.
If they don't remember what it is, or if they don't know what it is, they may be able to find out what it is at the "work" they got it from.
If you need a password but can't determine what it is, you can only legally change your situation by re-loading the original brand name software installation on the C drive, or by re-loading Windows from scratch from a regular Windows CD.
All 2000 and XP Windows installations have a default Administrator user, and at least one other user. You cannot delete that default Administrator user. You only have access to that user, you can only log on to that user, in Safe mode.