I noticed today on my MBP running Mountain Lion that using "Open With" (control+click on a file in Finder) showed duplicate entries for the file.

I’m unsure as to what I did that caused this problem to happen, though a recent thread on Apple Support Communities indicates it has something to do with clone images. I recently updated XCode through the App Store, and now have a duplicate entry for XCode when I do "Open With," so perhaps it’s happening when I update an application.

As one of the responses in the thread suggested, the solution for me was to run the following command in my Terminal window:

/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -domain local -domain system -domain user

I didn’t need to logout. I just relaunched Finder (control+option+click on Finder icon in the Dock) and the problem went away.

About the Author

Paul is the founder and chair for the Explore DDD conference. He co-founded and helps lead DDD Denver. Look for him speaking at local user groups, and at regional and international conferences.

If you are looking for an expert hands-on team coach and design mentor in Domain-Driven Design (DDD), BDD with Cucumber, or lean/agile process Paul is available for consulting and training through his company, Virtual Genius LLC.