I made a batch file that will:
Rename your original SOW directory so it won't be overwritten when you reinstall
Delete SOWGB registry keys from NorbSoftDev and from Matrix Games
This should allow you to reinstall the game from scratch.
I would appreciate if someone who knows what they're doing could test it to verify that it works. I tested it three times on my two machines. If you mess up at any point you can start again from the very beginning.
THIS IS ONLY TESTED ON WINDOWS 7 It should work on other versions of windows but it has not been tested that way.
Only use this if you have your game activation codes saved!
Download:
http://www.philipmcg.com/w3d/downloads/uninstall_sowgb.bat
Here's how it works step by step:
Save the batch file and then double-click it to run it.
Type "y" and hit enter to continue

Hit enter to finish this.

Download the SOWGB demo and Patch 1.5. Run the demo exe:

Let it install to the default directory

...

Uncheck the Launch Scourge of War box!

Now run the Patch 1.5 you downloaded:

Type your SOWGB Activation Code here:

...

Then run Scourge of War either by double clicking the exe, or using your new start menu shortcut.

