If you can find explorer.exe on the device, then maybe you can use CERegEdit to edit the registry of the device using an ActiveSync connection. In HKEY_LOCAL_MACHINE/init, find out which LaunchXX key has the value
launch.exe, and edit that value to
explorer.exe. That should result in the device booting to the core CE desktop when reset.
(I only recommend this if you're familiar with the Windows CE registry.
)