Check about:profiles to find out about the names. You need to replace 'profile' with the name of the profile. Add the parameter -p profile -no-remote to load a specific profile right away.The parameter -no-remote lets you run multiple Firefox installations side-by-side.

Add the parameter -p -no-remote to the end of the target line (leave a space) forces Firefox to open the profile manager on start that displays a list of all available profiles.

The Shortcut tab lists the target, and it is here that you add the instructions.

Windows users right-click on the Firefox shortcut and select Properties from the context menu.

The second option forces Firefox to load a specific profile or the profile manager on startup. Option 2: Adding a profile parameter to the Firefox shortcut You may also use 'launch profile in a new browser' to check it out without switching to it permanently. From 1 to 13 columns (on small tile size) - Change tile color. Drag and drop to change position of bookmark/folder. > start up box, drop down beside 'when firefox starts' has 3 options, make sure you don't have 'show my windows and tabs from last time' selected.

Select 'Set as default profile' to assign a new profile to the installation. I made a Opera like Speed Dial extension called Supa Speed Dial. the solution may be a simple oversight, you can choose a homepage as your start page OR multiple tabs as your homepage, you may just have the later selected.

If you cannot locate it using the folder name, you may use trial and error until you get the right profile, or use open folder to browse the profile folder and check it out.

The page displays the current profile at the top and any unused profile (that the current Firefox installation does not touch) below.

The page that opens displays all known profiles and the paths assigned to them.

Load about:profiles in the Firefox address bar.

Option 1: Set a default profile for Firefox in the interface

Firefox open multiple tabs on startup