With it you can remotely edit the registry using your desktop keyboard and mouse as opposed to using your stylus/keypad on your PDA or phone.

It's built as a Windows application which has been modeled after Regedit (with a few extra features such as favorites, value size, column sorting etc...)

It has been tested with Pocket PC and Smartphone on Windows XP/2000 and requires the .NET Framework 1.1 to run.

Update Description:
v1.11:
Features:
- Restart ActiveSync (Tools -> Restart ActiveSync).

Squashed Bugs:
- Deleting a registry key could cause MRE to stop responding.

v1.1:
GUI Tweaks:
- Create/Edit value dialogs now have the cursor set on the appropriate text box (one less mouse click).
- Reduced the size of the collapse button on the splitter. Primarily for those with smaller resolutions (800x600).
- Width of the registry tree saved.
- By default the list of values is sorted by name.
- Depending on the device type the tree icon is a phone or PDA.
- Connect dialog and registry tree now display the device name.

Features:
- Create keys/values.
- Delete keys/values.
- Rename value (thanks Pavel).
- Copy Key Name.

Squashed Bugs:
- The default value would sometimes be listed twice. Once as "(Default)" and again as "Default".
- When flipping back and forth b/t favorites and the reg tree the value list was not being updated.
- A truckload of error checking.