Set the default browser
Using Firefox
Most external programs will open links in Firefox if it is set to be the default browser. The How to make Firefox the default browser article describes how to use Firefox to set the system default browser.
Using your operating system
If after using Firefox to set the default browser you still experience one or more of the symptoms above, you can try to use your operating system to set the system default browser.
Windows:
Linux:
Ubuntu Linux
- In the System menu, open Preferences, then Preferred Applications.
- On the Internet tab under Web Browser, choose Firefox in the drop-down.
- Press Close.
Mac OS:
- From the Dock, open Safari.
- From the menu bar, click the Safari menu and select Preferences….
- Click the General icon, to display the General preferences panel.
- In the Default Web Browser: drop-down list, select Firefox.

- Quit Safari.
Windows:
Manually set File Types (Windows XP)
If links from programs like Outlook fail to open in Firefox, you can try to set the file handling options manually.
- Open Windows Explorer
- In the menu bar, click Tools > Folder Options…
- Click the File Types tab
- Find (NONE) url:Hyper Text Transfer Protocol, click it, and then click Advanced.
- Click the open action and click the Edit.
- Fill in the fields with this information:
- Action: open
- Application used to perform action: “C:Program FilesMozilla Firefoxfirefox.exe” -requestPending -osint -url “%1″ (Assumng you installed Firefox to the default location. If not, use your own path, surrounded by quotation marks)
- Use DDE: Checked
- DDE Message: “%1″,,0,0,,,,
- Application: Firefox
- Topic: WWW_OpenURL

Repeat steps 5 and 6 for the (NONE) url:Hyper Text Transfer Protocol with Privacy option.
Windows:
Troublesome programs
Some programs are hard-coded to open Internet Explorer rather than the default browser. Programs that do this are listed below along with possible solutions, if available.
- MSN Messenger
- AIM 5.9 – upgrade to the latest version of AIM.