It's good practice to have more than one account with administrator capabilities. If one account gets corrupted or you forget the password use the other to rectify it. Just a free tip for the future.
For now see if http://pogostick.net/~pnh/ntpasswd/ also works for Windows 7. If not, try the other ones from http://www.petri.co.il/forgot_administrator_password.htm (the above is #3).
Kees
forget my windows password, help me

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