What are you using that old version?

Firefox 31 and ESR 31 are the current versions.

https://support.mozilla.org/en-US/kb/set-how-firefox-handles-different-file-types?esab=a&s=mimetypes.rdf&r=0&as=s

Set how Firefox handles different types of files Learn to change how Firefox handles different types of files. For example, make a certain program always open PDF files or have Firefox download them instead.

It is a corporate environment. We are upgrading to a more recent version of Firefox with our new desktop solution but need to make changes to the default mimetypes file, estate wide, before the new version is going to be live.

Thank you for the link, although this shows how to update for a single user, we are looking to change the defaults for a corporate environment. We have the changes we need to make to the mimetypes file, but do not know how Firefox creates the default mimetypes.rdf for each user

Hi,

I am in the same situation than you but I forced firefox to take my own file if I remove it from my profile.

What i did: 1 Create my own custom mimetypes.rdf file. Firefox Interface - Options - Options - Applications... 2 Copy mimetypes.rdf in C:\Program Files (x86)\Mozilla Firefox\browser\Defaults\profile

So, if I remove the mimetypes.rdf file from my profile it takes from default location fine. However deleting the profile, opening firefox again it doesn´t use my own mymtypes.rdf file in the new profile, insteant it creates the "default installation" one.

On the other hand, I tried to set pdfjs.disabled = true from about:config, however although it sets the default PDF app "Adobe Acrobat", it doesn´t work. It doesn´t open any pdf file.

I am thinking to create an advertised shortcut in order to replace the mimetype.rdf when the user starts firefox (I distribute the firefox settings in a MSI) depending of the date of the file but it will take a few seconds each time the user run firefox. I really don´t like it...

Sorry for don´t help too much...

If anyone could post how firefox create mimetypes.rdf in new profiles...

I found this with a google search. Hope it helps:

http://mike.kaply.com/2012/03/30/customizing-firefox-default-profiles/

You can initialize a profile by creating a browser\defaults\profile folder in the Firefox program folder (C:\Program Files\Mozilla Firefox\) and place files like a user.js or a bookmarks.html file in it.

• http://mike.kaply.com/2013/05/13/more-major-changes-coming-in-firefox-21/
• http://mike.kaply.com/2012/08/01/major-change-setting-default-preferences-for-firefox-14/

You can also look at this extension:

• CCK2 Wizard: https://addons.mozilla.org/firefox/addon/cck2wizard/

Thanks for the links but my problem is that if I create a new profile it doesn´t take my mimetypes.rdf. On the contrary if I delete mimetypes.rdf from my profile and I open firefox, it takes it from browser/defaults/profile.

For any reason, when firefox creates a new profile it removes my file and it creates its own...

The second link is a good one but it is a UI version of about:config. It doesn´t configure the mimetypes.rdf

My version is 24.7.0

@AliceWyman Thank you for the link. I have also come across this link whilst searching Google but it does not advise what populates the mimetypes.rdf file. The default file template resides within the Omni.ja file but still none the wiser on what populates the data within on first launch

Look again at cor-el's post; https://support.mozilla.org/en-US/questions/1015378#answer-617455

If that can't help you, try this; Create a new profile. Then close Firefox. Copy the mimetypes.rdf file you want to use into the new profile (or any other profile) overwriting the current file. Then restart Firefox.

Anything useful here?

• http://mxr.mozilla.org/mozilla-release/source/uriloader/exthandler/nsHandlerService.js

Thanks but those links don´t explain how mozilla crates mimetypes.rdf when it creates a new profile.

However, I solved my issue (set Adobe Reader as default pdf application) with the setting pdfjs.disable = true in the config file and creating default mimetypes.rdf in browser/defaults/profile.

As I distribute the FX configuration by MSI, it will remove the user file from all profiles, when users start FX it will take my default mimetypes.rdf file. For new profiles due to the firefox preview is disable it will set Adobe Reader as default.