The iPAQ 110 Series Pocket PC can be hard reset by pressing and holding a series of hardware buttons on the exterior of the device.

First, power the iPAQ on. Next, press and hold the Windows, OK and Recording shortcut buttons (1 in the diagram above). Finally, while still holding the three shortcut buttons, press and release the tiny reset button on the right-hand side of the unit with a stylus or other small object (2 in the diagram above). Once you release the reset button, a screen should appear reading CLEAN BOOT in green text.
The Hard Reset is complete!