Cannot logon

My son gave us his old Dell Pentium II laptop computer with Windows 98. We uninstalled Walmart Connect then re-installed to eliminate his name from that program. During the process, we tried to add my husband’s name as a user with his own password. It would not accept it because it said he was not the system administrator. However, when we finished and re-booted the computer, it comes up with his name as the user name and won’t accept any password. Therefore, we cannot logon to the computer at all. Could you advise us as to how to remedy this situation. The only Window 98 disks we have to install are for a new PC and will not replace one already installed. Thank you for your time.