I am having lots of problems trying to associate a file type with a program. I have been developing a WPF program bridge.exe that uses a file with the extension ".ssn" as input. A week ago, I successfully associated the program with .ssn. The program is not installed in the system, but it ran correctly when I double clicked the .ssn file. I've been continued developing the program over this week, and today it was giving an error when I clicked the file. Eventually I realized that the current version of bridge.exe was not running - the one I had associated was in a different folder. So I tried to associate the newly built bridge.exe in the correct folder, but the old version kept running. So I tried to first disassociate bridge.exe with .ssn. I eventually discovered there is no way in Windows 7 to do this, but found this utility http://www.winhelponline.com/articles/231/1/An-Utility-to-Unassociate-File-Types-in-Windows-7-and-Vista.html However, the utility said .ssn was not registered on my system. So I searched the registry myself, found three entries for .ssn and deleted them. I then tried associating the current bridge exe. The old bridge.exe still ran on clicking the .ssn file. I decided to delete any old bridge.exe's, clear the registry, and try again. This time the Windows 7 file association GUI did not want to associate the current bridge.exe at all - it kept picking the first installed program Adobe Reader. It is as if it will only take bridge.exe from the original folder, and if it can't have that will not accept anything else. I am very confused by now. I can only assume the registry may be inconsistent. I can go back to a restore point just before I started doing this. But before I do this, does anyone have any ideas about what is happening, and what I can do about it?

Well, I have answered this to some extent. I found a few references in the registry under ...ssn_auto_file\shell\open\command to "K:\bridge\bridge.exe" and changed these to "K:\C#Progs\Bridge\bin\Release\Bridge.exe". Double clicking a .ssn file then ran the current version of bridge.exe in the ...\Release folder, and the application ran correctly. But I'm sure I shouldn't have to alter the registry to change the location of the program associated with .ssn files, so if anyone can shed any light on how all this works or point me to a reference, I'd appreciate it.

I found this thread http://social.technet.microsoft.com/Forums/en-US/w7itproappcompat/thread/b554b14b-e1fc-487c-b72e-28e4530b4413 which talks about something similar. It says that related functionality that was in XP has been removed, and that you may have to edit the registry directly.