Use FireFox as the Default Browser to Open Links

Question: "I use Firefox browser instead of Internet Explorer. When I would click on a link in an email, another box would open up saying something like "Locate Link Browser." (It would also open Firefox, but not without that annoying ‘open’ dialog box.) So, thinking that Outlook just wanted me to point to the firefox.exe file, I did that. Now every time I click on a link in an email it opens up in two separate Firefox browsers."

If you don’t have Firefox installed, the steps are the same to fix the problem. You can also try resetting Internet Explorer as the default. Look in IE’s Tools, Internet Options, Programs tab and click the Reset Web Options button.

Solution

From https://bugzilla.mozilla.org/show_bug.cgi?id=246078:

Open Explorer
Select Tools and then Folder Options
Select the File Types tab
Select Extension: (NONE), File Type: URL:HyperText Transfer Protocol
Click Advanced toward the bottom of the window
In the Edit File Type window, select open and click Edit
Clear the check for DDE above the DDE message box (which should contain "%1" or similar)
Click OK, Click OK
Repeat for File Type: HyperText Transfer Protocol with Privacy and FTP

The dialog in Step 7 will resemble this, remove the check from the Use DDE which is highlighted in the screenshot:

Set Program Access in Control Panel

Windows XP and Vista allow you to control program defaults through Control Panel, Add and Remove Programs, Set Program Access and Defaults. If the above method fails, use this method to set the default browser.

More Information

Should you reopen the Edit dialog after returning to the File types list dialog, the DDE box may be checked and the Application name is changed to FIREFOX. This is the correct setting.