I moved to a new pc but have the FF profile from the old one and how do I find out which FF version the old FF was?

Question

I want to use the old version of FF from my previous pc. I saved the profile folder etc on the old pc. The old HD is attached to the new pc via USB. How do I tell what version the old one was?
After installing the old version on the new pc I want to use the former FF profile file on the new pc installation of FF.
I have the sessionstore backups etc. from 3/21.
BTW I typed all this info earlier and support automatically butted in with a guess to what would be an answer. And in the process overwrote what I typed. Please try to get mozilla to prohibit this behavior.

Answer 1

Sorry to hear that the forum lost your question.
I'm not sure I understand why you need an old version of Firefox. Were you way behind in updates? Normally when you install the current version, it will seamlessly update/convert any obsolete files in your profile folder to current versions.
Perhaps I'm answering the wrong question. If the question is: "how do I get a new installation of Firefox to use all my old settings" then I can give you a way to do that.
''This assumes you might have data in your new Firefox that you don't want to overwrite and preserves your current profile.''
Go ahead and open your old profile folder in a Windows Explorer folder. At this level you should see a bookmarkbackups folder, among others. Later you'll copy the ''entire contents'' of the old profile folder to a new location on your C drive.
'''Overview'''
These are the steps:
# Create a new Firefox profile
# Remove everything from that new profile folder
# Copy in everything from the old profile folder
'''Create a new Firefox profile (Windows)'''
Exit Firefox and start up in the Profile Manager by pasting the following into the Start menu search box (or Run dialog) and pressing Enter:
firefox.exe -P
''Do not delete anything here! Any time you want to switch profiles, exit Firefox and return to this dialog.''
Click the Create Profile button, assign a name like OldSettings, and skip the option to change the folder location. Then select that new profile in the dialog and start Firefox.
'''Open the New Profile folder in Windows Explorer'''
Firefox in the new profile should look like a factory fresh installation. Open the Troubleshooting Information page using either:
* "3-bar" menu button > "?" button > Troubleshooting Information
* Help menu > Troubleshooting Information
* type or paste about:support in the address bar and press Enter
In the first table, click the "Show Folder" button. Firefox will launch your brand new profile folder in Windows Explorer.
Leaving that folder open, switch back to Firefox, and Exit. Either:
* "3-bar" menu button > "power" button
* (menu bar) File > Exit
When Firefox closes, the profile folder should be front and center, or you can activate it using the Task bar.
'''Copy Old Data in Place of New'''
In that new profile folder, select all the contents and delete.
Leaving that window open, switch over to your old profile folder. At this level you should see a file named places.sqlite. If that isn't visible, try moving up a level until you find it.
Select everything (Ctrl+a) and Copy (either right-click > Copy or Ctrl+c).
Switch to the empty new profile folder in other window and Paste (either right-click > Paste or Ctrl+v). This may take a minute since some of the files are large.
'''Start Firefox'''
Firefox should start up in that new profile with the resurrected old profile data. Success?