I did it. My mistake. Long story short I removed permission from the Administrator to administrate. I cannot access the security center, upgrade, change, restore, or take ownership. I just rehabbed this old ThinkCentre m 8122. No conflicts, all was great til my screw-up. Please help.
log in to the hidden Admin account that Windows Setup creates by default, then change permissions for your own user account.
When done, restart normally: http://windowsxp.mvps.org/admins.htm