I found this snip from a site, Which may let you be able to get into Admin account and let you change account settings.
Assuming you are on XP or later.
"Enabling the built-in Administrator - The first thing to do is see if the Administrator account is enabled by going into Safe Mode. If there are no administrative user accounts on the system, the built-in Administrator may become enabled there. To get into Safe Mode, repeatedly tap the F8 key as the computer is starting up. This will get you to the diagnostic menu. Select Safe Mode using the arrow key. If you see an icon for Administrator on the Welcome Screen, click on it. The default password is a blank. Then go to Control Panel>User Accounts and make changes."
Edited by Disturbed117 - 6/20/13 at 9:53pm