Firefox, Outlook and “General Failure”

Yes, I still use Microsoft Outlook. It provides me with one app for my email, contacts, calendar, RSS feeds and tweets. So there. But there’s one well-known (and years old) bug that sometimes drives me insane: when you click a hyperlink in an email, RSS post or tweet in Outlook, you get one of the following error messages:

General failure. The URL was: "http://www.domain.com" The system cannot find the file specified.

or

General failure. The URL was: "http://www.domain.com" An error occurred in sending the command to the application.

(Obviously, “www.domain.com” is an example. The address in an actual error message will vary.)

This happens because the Registry key that tells Firefox that it’s the default browser becomes corrupted or changed by some other program. I don’t know how to fix this in Windows XP, but the solution for Windows Vista and Windows 7 is pretty easy:

1) Close Firefox and Outlook, and then open Regedit.

2) Navigate to HKEY_CLASSES_ROOT\FirefoxURL\shell\open\ddeexec

3) Look for the “Default” entry in the right pane. The value will probably be an odd string of letters, numbers and symbols (such as “%1”,,0,0,,,,). Remove whatever text you see in this entry, then click OK and exit Regedit.

4) Restart Firefox and Outlook.

I get this problem on my computer once every six months or so, and this has always fixed it.