The arrival of a new media volume or newly attached device is detected. The media or device is scanned in order to determine the type, and a complete list of installed software programs registered to handle the media type or device is presented to the user. This list may be generated and displayed while the disk is still being scanned. The user selects a handler for the media type or device, and may also decide if the handler will be the default handler when media type or device is subsequently encountered. The user may check and update the stored user settings to view or edit the default handlers for any media type or device. Additionally, the user is prompted to confirm or change the default handler after another registered handler of that media type has recently been installed on the machine.