
Run OnyX.

Open the Automation panel or open the Maintenance panel and select the Rebuild tab...

Check the "LaunchServices" case and uncheck the other cases.

Click the Execute button.
If the "Open with" contextual menu of the Finder displays duplicate applications, or applications which are not installed (anymore), OnyX cans help you correct the problem. You should let OnyX rebuild the LaunchServices database.
Run OnyX.
Open the Automation panel or open the Maintenance panel and select the Rebuild tab...
Check the "LaunchServices" case and uncheck the other cases.
Click the Execute button.