forgot Windows XP Home Edition Administrator password and cannot access

I’m trying to fix my little sisters computer. We just hooked it back up and now can’t logon. I’m trying to reset the administrator password, but can’t get into the control panel. I used ctrl/alt/delete to get to the default login. The username says blonde01, but she cannot remember the password. Is there a way to reset it? We also cannot find the windows xp disc.