To perform a master reset on the handheld, follow these steps:
IMPORTANT: All application data is lost and e-mail service and other services disable when performing a master reset. Back up contacts, calendar appointments, and other data to your computer before continuing.
From the Home screen, press the Menu key.
Scroll to and select the Options icon.
NOTE: Press the trackball to select.
Scroll to and select Security Options.
Select General Settings.
Press the Menu key.
Scroll to and select Wipe Handheld.
If desired, scroll to and select the Include third party applications check box.