This is the term in Firefox Downloads. When I click on the Open Containing Folder icon next to a downloaded file, I get an error message: "This file does not have a program associated with it for performing this action. Please install a program or, if one is already installed, create an association in the Default Programs control panel." It's not an issue of the extension of the downloaded file, because I get this error regardless of the type of file downloaded. Also, in another program (qBittorrent) I have a similar issue. There it's "Open Destination Folder" and selecting that from the right click menu yields nothing, not even the error message. I suspect a Registry key. Any ideas?