The sessionstore.bak file hasn't been used since around Firefox 33. All the action is in the sessionstore-backups folder. Did you back that up or can you do that now?

Here are the types of files you normally find, and the key thing is the last modified date.

• recovery.jsonlz4: the windows and tabs in your currently live Firefox session (or, if Firefox crashed at the last shutdown and is still closed, your last session)
• recovery.baklz4: a backup copy of recovery.jsonlz4
• previous.jsonlz4: the windows and tabs in your last Firefox session
• upgrade.jsonlz4-build_id: the windows and tabs in the Firefox session that was live at the time of your last update
• various .js files from Firefox 55 or earlier

Sometimes there may be "numbered" files, for example, recovery-1.js, when the main file cannot be updated.

To preview the contents of a file, you can drag and drop it onto this page, then click Scrounge URLs: https://www.jeffersonscher.com/res/scrounger.html

That tool is on my site, so please let me know if it doesn't work for you.

Can you find a file with the tabs you want?

No, unfortunately the files that matched the date is not correct, they don't have the tabs i want. All the tabs are still the old one, it is not the one i had before I forced-restart my computer

Sometimes in a crash the file becomes corrupted; if that's the case, they're probably gone. If you extract the latest useful set (maybe using an upgrade... file) and then check your history for other pages you visited, hopefully you can recover most of the tabs.

You can check if you have an "Old Firefox Data" folder on the desktop in case the Refresh feature in Firefox has been used and a new profile has been created.

• https://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-most-problems

You can check if you have an older copy of sessionstore.js available as part of a system restore point.

• System Restore Explorer:
  http://nicbedford.co.uk/software/systemrestoreexplorer/