That feature was removed in Firefox 4.

Thanks. That seems a bit odd, though. I was using it today at work in Firefox 8.0

Was there any discussion as to why this was removed?

the-edmeister - I do not understand your answer. "Set as Desktop Background" is still available in Fx9.0.1. W7x64.

Right, something odd is happening here. I went over to my other computer (also running Windows XP & Firefox 9.0.1 and "Set As Desktop Background..." IS there. Somehow the Firefox installation must be messed up on this computer or the feature is simply not available for non-admin accounts on Windows starting in later versions of Firefox. I know that on this same computer with the non-admin account with Firefox 8 I WAS able to see this command.

And another datapoint. On the computer where this is missing from the context menu I have logged into an admin account and Set As Desktop Background is also missing there. So, this is NOT related to account type. One interesting fact about this computer is that this is a recent install and it started at Firefox 9.0.1. I had a hard drive fail and so the Windows XP and Firefox installs are fresh.

Create a new profile as a test to check if your current profile is causing the problems.

See "Basic Troubleshooting: Make a new profile":

• https://support.mozilla.org/kb/Basic+Troubleshooting#w_8-make-a-new-profile

There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems.

If that new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.

See:

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox