Open multiple Firefox windows/instances?

[Rekrul]

I'm asking this for a friend...

How can you get the Windows version of Firefox to open multiple windows/instances when double-clicking Desktop shortcuts rather than just creating new tabs in an existing window? My friend swears that Firefox used to behave this way previously, now it doesn't and she wants the old behavior back.

Some backstory: She had her system set up exactly the way she wanted, then recently, she had a guy over to work on it and he screwed it all up such that he needed to re-install Windows 7 from scratch. This also meant that all her programs had to be re-installed from scratch (since he didn't bother to backup anything). Now she swears that Firefox behaves differently than it used to.

What she wants is if she has a copy of Firefox running and she double-clicks a Desktop shortcut to a specific website, she wants it to open in a separate window. Or if she double-clicks the Firefox shortcut, she wants a new window to open. She doesn't want each one to have a separate profile, she just wants separate windows.

I know someone is inevitably going to ask why she wants this and explain how tabs are better, so... She says that it's less confusing for her. Sometimes she's on a site like YouTube watch videos and She'll suddenly get the urge to go another site, so she uses the shortcut on her Desktop, looks at that site, then thinks "I'm done" and closes the window, closing all the tabs in the process.

Yes, I know there's a setting you can change to warn you before doing that. That's beside the point. Is it possible to have each shortcut open a new window/instance using the same profile?

[BobbyPhoenix]

Should be able to right click, and select "Open in new window".

[morat]

You can use the -new-window <url> command line argument.

Command Line Arguments
http://kb.mozillazine.org/Command_line_arguments

Try changing the browser.link.open_newwindow.override.external preference to 2.

More info
http://superuser.com/a/639403

[Rekrul]

She never had to do anything special in the past. Any time she saved a link to a website to a Desktop shortcut and then double-clicked it, Firefox would open a new window.

She doesn't like using tabs for different websites in the same window and wants each shortcut to open a new window without having to edit the shortcut, use the command line or anything else.

Is this possible?

[DanRaisch]

See if anything in this thread meets their needs -- https://support.mozilla.org/en-US/questions/1258193