There is only one way to do a hard reset, or cold boot, on the WPA 1200.  This method will wipe all data from the handheld and return it to its factory default settings:  

On the device press and hold the "Func" key and the "Backspace" key. While continuing to hold those keys, insert the stylus into the reset hole on the back of the unit. Press the reset button with the stylus and continue to hold the two buttons on the front of the device. The device will power back up and then it should come to the calibration screen for the touch screen. Now you can release the buttons and calibrate the screen, time, and date.

A good way to double check that everything was reset is to go to the list of programs. If the reset worked correctly, you should see no Wasp software listed. If you still see Mobile Asset or Inventory control, the unit was not completely reset and you need to start over.