The actual title of this post should probably be something like *If the **Open with…** contextual menu has duplicate entries in it, then do this.” But that seemed overly long. The problem with mentioning *Launch Services* is that most people don’t know it’s there and that it’s responsible for such things. Here’s a better way to do this, if you get a contextual menu in the Finder which looks like this:
And you want to do something about it,
and you want to attend to the fix yourself,
and you aren’t afraid of the terminal…
*Then*, you can do this: open up a terminal window (look in the Utilities folder inside the Applications folder [CMD + SHIFT + U]), and paste the following code in the command line:
/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -domain local -domain system -domain user
It’s long, but it needs to be just that way. Press return. Wait a second or two for the command to complete. You will know it’s done when the prompt comes back, indicating that it’s ready for another command.
*Then* simply re-launch the Finder. (Under the **Apple** menu, go to **Force Quit…** and you will see *Finder* listed as one of the apps that can be quit, or in the Finder’s case, re-launched.) You do not, as other instructions around the web indicate, need to log out and back in, nor do you need to re-start your machine. Running the command above and re-launching the Finder is all you need to do.