I created a thread in the Z series that presents an automated script to remove the security password on many WinCE based units. It should work fine for the X series - X910, X920, X930, X940. I don't know if it will work for the X900 or the X700 units.

No need to install Condi's Hackmode or learn the complexities of TestMode. It removes the password entirely - unlocking the unit. It also saves the existing PASSWORD.DAT file (on the SD) before removing it.
Security Password Removal Script

I'm closing this thread so all comments should be posted in the original thread.