See this - https://developer.mozilla.org/en-US/docs/Mozilla/Command_Line_Options#-setDefaultBrowser

Sorry, I need to do this for Mozilla Firefox 17.

You are using Firefox 3.6, which is no longer supported. Please update to Firefox 24 and Flash 11.8 IMMEDIATELY or switch browsers.

I'm trying to install firefox 17.0.1 on computers that never had firefox, and I need to set default browser from command promt.

I try the command -setdefaultbrowser but don't work.

I'm trying to install firefox 17.0.1 on computers that never had firefox, and I need to set default browser from command promt.

I try the command -setdefaultbrowser but don't work.

Hello, are you sure that you give the correct command ? :

• firefox -setdefaultbrowser

thank you

Yes, I have proved that in the 17.0.1 version of firefox, this command does not work properly. Seems to be a documented bug.

-setDefaultBrowser is the correct command - you need the two capital letters.

Why Firefox 17.0.1? You would be missing a number of important security updates. Firefox 17.0.9 is the current ESR release version.

I have verified that with two capital letters or not, the command fails. I need to install version 17.0.1.

Firefox 24 is actually the current ESR, 17 will be end of life soon. Please install a current version of Firefox, not something going away in a few weeks.