This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

Default application for .pdf switch to Firefox after computer restart.

  • 1 reply
  • 1 has this problem
  • 5 views
  • Last reply by FredMcD

p.wojdacki
p.wojdacki
more options

Hello. Despite setting the default program for opening PDF to my own application in Settings -> General -> Application, the default program always changes to FireFox after restarting the computer.

How to set the selected program permanently.

Is there one somewhere in [about: ..]? Maybe something in the windows schedule

Hello. Despite setting the default program for opening PDF to my own application in Settings -> General -> Application, the default program always changes to FireFox after restarting the computer. How to set the selected program permanently. Is there one somewhere in [about: ..]? Maybe something in the windows schedule

Chosen solution

Are you talking about the computer's default setting or the Firefox setting?

>Browser Deleting mimeTypes.rdf will reset all download actions to the default settings. In Firefox v55+, the file name was changed to handlers.json


Type about:support<enter> in the address bar.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the above file. Then rename or delete it. Restart Firefox.

Read this answer in context 👍 1

All Replies (1)

FredMcD
FredMcD
more options

Chosen Solution

Are you talking about the computer's default setting or the Firefox setting?

>Browser Deleting mimeTypes.rdf will reset all download actions to the default settings. In Firefox v55+, the file name was changed to handlers.json


Type about:support<enter> in the address bar.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the above file. Then rename or delete it. Restart Firefox.