My setup project creates certain directory under user app data dir.
I added MessageBox custom action, which asks user if he wants to keep or delete settings and projects, which are stored in the mentioned directory.
Output property of this message box custom action is REMOVE_SETTINGS and clicking Yes button sets it to IDYES. I know this because I added another MessageBox custom action just to show the value of this property.
Under Operations Tab for the mentioned directory, I checked remove folder. Condition is REMOVE_SETTINGS = IDYES, Always remove folder, I selected component which is always installed / uninstalled, and selected Remove on: Component Uninstall.
Directory is never deleted.
I sent the project file for another ticket I have open on the forum.
Thanks.