The profiles.ini file is simply a file that tells Firefox where each profile folder is stored. This is always done as a single file in that specific location on your computer along with the installs.ini file to determine what profile needs to be used for which installation of Firefox.

What I think you are thinking of is the actual profile folders themselves. In Windows, those folders will be stored in the following location on your computer:

%appdata%\Mozilla\Firefox\Profiles

These are the folders that actually hold your Firefox data (bookmarks, passwords, history, etc). They are kept separate of each other and there will be a folder for each profile that you have created.

Hope this clarifies things.

What I think you are thinking of is the actual profile folders themselves. In Windows, those folders will be stored in the following location on your computer: %appdata%\Mozilla\Firefox\Profiles

No I'm not talking about profile folders. I do know that they are stored at different location and a different folder is created for a new profile.

I am talking profiles.ini, and I think if one install FF 77.01 version in a folder named: Firefox-77.01

and the second installation is done in another folder named: Firefox-80.0.1

then there should be two different profiles.ini because technically these are two different software (or in other words two different versions, isn't?

Where did you read about multiple profiles.ini files ?

Firefox always has used one profiles.ini file for all Firefox versions you have installed and this includes developer builds like Nightly and Beta and Developer Edition. However current Firefox releases can lock a profile to a specific installation folder and will not use a profile that is locked to another installation.

• https://support.mozilla.org/en-US/kb/dedicated-profiles-firefox-installation
• https://support.mozilla.org/en-US/kb/understanding-depth-profile-installation

Where did you read about multiple profiles.ini files ? Firefox always has used one profiles.ini file for all Firefox versions you have installed and this includes developer builds like Nightly and Beta and Developer Edition. However current Firefox releases can lock a profile to a specific installation folder and will not use a profile that is locked to another installation.

• https://support.mozilla.org/en-US/kb/dedicated-profiles-firefox-installation
• https://support.mozilla.org/en-US/kb/understanding-depth-profile-installation

1. I read in Firefox documentation couple of months ago and afterwards I tried to install multiple times but it never happened whereas the FF documentation clearly states it can create a separate profiles.ini file for each new installation of FF version.

2. The profile locking feature which you mentioned, I guess you're talking about creating different profiles via profile manager firefox -p If so I've been using it for last many yrs even when firefox used to store all data in on profile folder.

Thank you

Quote: ... whereas the FF documentation clearly states it can create a separate profiles.ini file for each new installation of FF version.

You are confusing profile folders with the profiles.ini file. Windows hides the .ini file extension by default and that might add to the confusion. There is only one profiles.ini, but you can create as many profiles as you like that are registered in profiles.ini with the names as shown in the Profile Manager and mapped to a folder on the hard drive.