Problem with .edpi file association

[arobustus1]

I now have to bite the bullet & use Windows 7.
After installing ExamDiff Pro I noticed that the .edpi extension had no association. I used W7 to associate w/EDPro but that made it so the .edpi itself file was always the first file to be compared. That is the first dropdown contained "Whatever.edpi". I finally went through the registry & got back to square 1. But now if I click on an .edpi W7 wants to know what to use to open it, as before.
If I open EDPro & navigate to the .edpi file it opens just fine, but I no longer have that super-handy one-click feature the way I did on my previous computer (XP). How do I get back to those halcyon days?
Thank You,
-plh

[psguru]

The following key is created when ExamDiff Pro is installed:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\.edpi]

[HKEY_CLASSES_ROOT\.edpi\shell]

[HKEY_CLASSES_ROOT\.edpi\shell\open]

[HKEY_CLASSES_ROOT\.edpi\shell\open\command]
@="C:\\PROGRA~1\\EXAMDI~1\\ExamDiff.exe /sf:\"%1\""