This is a Halo 2 Map Resigner Context Menu Windows Shell Extension. How it works, is you can right-click on a .map file, and choose Resign Map from the list of options that appear. Once the Resigning operation is complete, a message box will display the map's new signature.
This requires .NET Framework 4.0
How to install:
Download and extract the ZIP archive, and extract it to a folder.
Run Halo 2 Map Resigner.exe.
In the Menu Bar, choose Tools and then Install Windows Explorer Extension.


I am also going to post the source code for this project, if any of you are interested in Shell Programming at all.