For XP Home I boot safe mode and change it.
For other versions I boot up NTPASSWD (see google) since it's free and gets it done in about 2 boots.
I forgot my password for the administrator and i need it fast because i have some business to take care of. I used Austrumi to change it but when i went on the boot menu, i keep getting a message saying it failed to copy my registry. how can i fix this