Soft Reset O2 XDA (HTC Wallaby)
If your O2 XDA (HTC Wallaby) is stuck or frozen, You can perform a soft reset operation. Check out how to force restart WindowsCE. As a result your O2 XDA (HTC Wallaby) should reboot and start running again. Click here to find out more about soft reset operation.
Open the Stylus and use the half with smaller point.
Use Stylus and putit into the hole on the bottom right side of the phone (on the picture).
Done, ur device must reboot now.
Soft Reset (O2 XDA (HTC Wallaby))