C:\Users\Al\AppData\Roaming\Mozilla\Firefox\Profiles\s99pq6qr.default

The problem is that it had 2 profiles on the new computer...mine & a generic one ..& that generic one became the starting or DEFAULT profile... obviously without all my data....so I backed out & later deleted that one generic profile so mine would be the only DEFAULT profile used. 

https://support.mozilla.org/en-US/kb/switching-devices

Click the menu PhotonMenuButton button in the top right corner of the screen.
Click Help.
Click Switching to a new device.

& on the internet....

Here's what happened: I had installed Firefox on a different computer using my current profile backup copy/pasted, into C:\Users\Al\AppData\Roaming\Mozilla\Firefox\Profiles\s99pq6qr.default & it worked ok .... but when I signed out & back in days later & launched Firefox on the new computer... The problem is that it had 2 profiles on the new computer...mine & a generic one ..& that generic one became the starting or DEFAULT profile... obviously without all my data....so I backed out & later deleted that one generic profile so mine would be the only DEFAULT profile used. But from then on trying to use my profile on the new computer copy/pasted from my main laptop that I’ve had FF on for10 years...failed .....as it kept using the generic one...& all attempts at fixes to get only my backup profile used didn’t work...so.... & had to do a complete uninstall of Firefox using REVO..as it finds all folders & files hidden around places....but ....after REVO uninstall I found more folders &files of Mozilla & Firefox all around in my C drive...SO..after eliminating everything I could & starting over ...by downloading a new Firefox browser application on the new computer ...but before running the set up files... Now... I want to reinstall Firefox on this different computer ....& make sure that only my backup profile is used! I was going to try Backup assistant.... But HOW DO I LOCATE & USE/RUN Backup assistant? When I read this: https://support.mozilla.org/en-US/kb/switching-devices These are the steps you need to follow: Click the menu PhotonMenuButton button in the top right corner of the screen. Click Help. Click Switching to a new device. BUT...I DON’T WANT TO “Switch to a new device.” I WANT TO KEEP IT AS IT IS ON MY CURRENT DEVICE ....AND...WHILE ADDING IT TO MY NEW COMPUTER TOO (I might be confused at the term 'switch') Then I thought of using Sync When I read this about Connect additional devices to Sync: To connect another desktop computer or profile, just sign in and let Sync do the rest. https://support.mozilla.org/en-US/kb/how-do-i-set-sync-my-computer How do I know if I already had set up Sync on my computer? how to access it I’m sorry.. but just overwhelmed/confused with too many help articles here... & on the internet.... Thanks for any help & suggestions!