Ways of getting Admin Control Mode.

After reading info and documentation it seems to me that these are the ways of setting a remote computer in "Admin Control Mode":

1. Going phisically and make a "ctrl-p" bios setup.
2. Purchasing a valid certificate and configure remotely via RC server
3. Sending a usb key with PID-PPS pair and then configure remotely

It's that correct? are there any other methods?

Thank you!