From MozillaZine Knowledge Base

How do I make Mozilla my default browser?

The first time you run the browser, it should ask you if you want to make Mozilla your default browser. If you answered �no� and later decide you would like it to act as your default browser:

• Windows: go to Edit | Preferences | Navigator. Click Set Default Browser.

• Mac OS X: go to the Apple menu | System Preferences | Internet | Web | Default Browser | Select.

• GNOME (Unix/Linux): Open the Control Panel. Go to Document Handlers | URL Handlers | Default: gnome-moz-remote --newwin %s .Then put the following text in ~/.gnome/gnome-moz-remote (create the file if it does not exist):

[Mozilla]

filename=absolute path of Mozilla install directory/mozilla

See also

• Default browser