Sometimes you cannot associate a program with an extension in Windows 7

This article provides a solution to an issue where you're unable to associate a file extension to an application in Windows 7.

Applies to:   Windows 7 Service Pack 1
Original KB number:   2159999

Symptoms

You may not be able to associate a file extension to an application in Windows 7.

Cause

This may occur if the program you are attempting to associate with is not registered correctly.

Resolution

Follow the steps below:

1. Type regedit in the Run line or from an elevated CMD prompt.
2. Navigate to Computer\HKEY_CLASSES_ROOT\Applications and find your .exe name.
3. Navigate under its name to shell> open> command.
4. Under Default, make sure the application location points to the actual location of the executable.
5. Press OK and then try to reassociate the file type as you normally would.