Hello About AutoPlay. https://support.mozilla.org/en-US/questions/1517807 About Disable Autorun. Maybe, take a look at your download actions. https://support.mozilla.org/en-US/kb/change-firefox-behavior-when-open-file#w_changing-download-actions For information purposes. What information is stored in my profile? https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data#w_what-information-is-stored-in-my-profile <blockquote>Download actions: handlers.json This file stores your preferences that tell Firefox what to do when it comes across a particular type of file. For example, these are the settings that tell Firefox to open a PDF file with Acrobat Reader when you click on it. For more information, see Manage file types and download actions in Firefox.</blockquote> You can try Go to your profile folder https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data#w_how-do-i-find-my-profile Then, shut down Firefox Then, in your profile folder, delete the file '''handlers.json''' or rename the file (for example) handlers.json-old Next, start Firefox Next, go to your download actions, the actions will be reset Next, perform your checks handlers.json will be automatically recreated.