Hi, could you double-check two things:

(1) Default profile setting on the built-in profile manager page

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

This is the profile in use and it cannot be deleted.

If this profile has a Set as default profile button, go ahead and click that.

(2) Shortcut you use to start Firefox

There is a flag you can add to the command line to pop up the external profile manager. Let's make sure that you do NOT have that. To call up Properties:

• right-click a desktop shortcut > click Properties
• right-click a Taskbar icon > right-click the Mozilla Firefox item on the menu > click Properties

Windows should show the Shortcut tab by default but, if not, select that tab.

The Target line usually will have one of these:

• "C:\Program Files\Mozilla Firefox\firefox.exe"
• "C:\Program Files (x86)\Mozilla Firefox\firefox.exe"

If there are any parameters after that -- especially -P -- go ahead and remove those.

I tried your options (1) and (2). For option (2) I right clicked a Firefox icon that was on the taskbar; that was the icon I always used and there was never any other Firefox icon on the screen. Right-clicking that icon did not give a menu, although (2) had said there would be a menu.

Then I noticed that another Firefox icon had appeared, this one on the desktop; it seemed to have arrived only today. This one had the title of the profile that I had removed a few days ago. I right-clicked it, got the menu, clicked Properties, deleted a -P, all according to your option (2). Then I left-clicked this icon and Firefox opened immediately as it should. I then deleted the icon of the taskbar and dragged the other onto the task bar.

Problem solved. I could not have fixed this problem without your directions. Thanks!