Resetting Admin Password on Windows Embedded

I'm trying to fix a guest computer in the lobby of my wife's hotel. Some guest has it messed up. Seems that whoever installed the computer set a new Admin password on it that I don't have.

Here's the kicker. It's Windows Embedded, which is on a small mini computer with no cd drive, only a few usb ports.

Anyone know of a free way to reset the Admin password on this thing?