How to change a file's “open with” setting to another instance of the program with the same name?

Question

I have 8 versions of a particular piece of software installed (versions 5.1.0 through 5.1.7). I need all versions installed so I can occasionally test using the older versions. They're all in separate directories, but the executable is named the same in each of them.

Windows 7 is convinced that I want to use version 5.1.6 to open .proj files. I'd like to change this so it uses version 5.1.7. I tried all possible ways according to this question: Remove default "open with" setting.

But it won't "stick". I can change the default program to something entirely different, like a text editor, and that works as expected, but not to another version of the same executable name.

I hit "Browse" on the "Open with" dialog, go into the 5.1.7 folder, pick the executable, and then hit OK. Back in the "Open with" dialog though, it still has the same Recommended Program highlighted, instead of the one I just picked.

Answer 1

I changed the pathname in the registry for these keys:

• HKEY_CLASSES_ROOT\Applications\emergent.exe\shell\open\command
• HKEY_CLASSES_ROOT\proj_auto_file\shell\open\command

And that took care of my problem.