I've called the big guys to help you. Good luck.

Anything?

This usually depends on how a server sends the file. If the file is send with a supported file type then it should work. If files are send with a generic MIME (content) type like "application/octet-stream" or a content disposition header then this probably won't work.

• http://kb.mozillazine.org/File_types_and_download_actions
• https://support.mozilla.org/kb/change-firefox-behavior-when-open-file

In my first post I state that I went under the applications settings, and that there is possibly a bug with the menu. Look at the pictures.

Also, this happens even with .mp3 and .wav files, every time I download something, the prompt appears and "Do this automatically for files like this from now on." defaults to being checked, yet it keeps prompting me what to do, it's not just with the .tvc files.

You can try to rename (or delete) the mimeTypes.rdf file in the Firefox profile folder to reset all file actions.

• http://kb.mozillazine.org/mimeTypes.rdf
• http://kb.mozillazine.org/File_types_and_download_actions#Resetting_download_actions

I understand that there is a suspicion that there is an issue with the menu, however sometimes when preferences do not save it can be caused by a locked preference or how the server sends the file as corel has mentioned.

Renaming the mimetype file is one of the recommendations when that preferences file in your profile becomes corrupt, renaming it will tell it that is the issue. It also sounds like the preferences are not saving:

• How to fix preferences that won't save

It is even more suspicious that this is happening for other file types. Please post back with the results of trying to generate a new file.

I completely reset my Firefox, no change, still keeps popping up to ask me what to do, even if I've already specified to automatically open.

Check your computers associations. On Win 7, its;

Control Panel\All Control Panel Items\Default Programs\Set Associations

Just did, .tvc opens Teamviewer as it should.