YOU NEED PHYSICAL ACCESS TO THE COMPUTER TO DO THIS!

Anyway, how to drudge into a computer as an ambassador after the password:

Step 1: Turn the computer on.

Step 2: Spam F12 a agglomeration of times, until the avant-garde startup card comes up.

Step 3: Boot the computer into safe mode.

Step 4: Log into the annual alleged "Administrator". There's a 99% adventitious that the annual will not accept a password.

Step 5: Go into the ascendancy panel, change the administrator's annual password.

Step 6: Reboot normally.

Step 7: Use the countersign you put in with the ambassador annual you targeted.

Step 8: Enjoy!

PS: I've alone activated this on XP, not abiding about Vista or any added OS.

PPS: If they accept the "Enter your username and password" login thing, again advance Ctrl + Alt + Delete to go to the added log in screen.