Admin lockout

I’m working on a 2nd hand pc bought by a friend, it has win98 installed but unfortunately the previous admin has set a password and locked out several functions for his use only including network and display settings. To make things difficult thereare around 35 different user profiles and pwl files as well so I don’t even know who the admin logged in as previously. Is there a way to reset/delete these short of wiping the hdd and starting afresh?