Step 5: The Guest Account Method
If nothing so far has worked, but there is a non-passworded guest account, you may have hope yet.
Go into the guest account, click the start menu, click run, and then type in "cmd". A black window should pop up.
Then, after typing "net user administrator *" , press enter and you will be given directions to create a new password for the administrator. After typing in the new password, press enter and close the window. Log off, then get into the administrator account with the new password.