I had need to use the Restore system option recently. Since then I have lost the file association of .max file with 3DStudio Max. When selecting an app through the Open With ... Browse window - selecting the correct exe file does not seem to fix the file association. That is after that operation - double clicking on a .max file does not activate the 3DStudio Max application.
The Max application does not show up in the file llist - I have to Browse to it.