HP will tell you there's no way to hard-reset the 112 but
Lon Hon Chun found this method after some intensive web searching:
To hard reset a HP iPAQ 112
1. Press Win + OK + Record together
2. While doing that, press reset button and hold for 3-4 seconds
3. Release reset
4. Release buttons
The screen shows "CLEAN REBOOT"
Looks like the finger dance all over again. 0X
HTH