[Brief Background] My Windows 8 recently restarted while I wasn’t looking. So I knew that my tabs would not restore if I were to open firefox, and it would not even give me the option to restore them. So (in order to prevent any backup files from being overwritten) I used Internet Explorer to look and see if anyone knew how to fix this problem. Unfortunately some advice was outdated. Also unfortunately, when I did what I thought would work, the session restore page came up but did not list any tabs to restore. No one seemed to have an easy solution for that situation, but I found one.
First (to make sure that my restore files didn’t get overwritten and lost) I copied backups of firefox’s “profile folder”, the place where session restore files are stored, and put a copy on my desktop.
Then, use firefox for a bit, open some tabs that you don’t really need, and induce a “crash”. To Induce a fake “crash”, use control-alt-delete to bring up the Task Manager, go to the “details” tab of the Task manager and select the firefox program and click “end task”, and when it asks if you are sure you want to end task, confirm that you do want to end task.
Now when you open firefox there should be a properly working session restore page that is ready to bring back all of those tabs (from the step above) that you didn’t need.
Now you can find the file that it is using. The time stamp on the file will say that it was created around the time you did this. Look in somewhere like:
C:\Users\YOUR USERNAME HERE\AppData\Roaming\Mozilla\Firefox\Profiles\awkgm9m1.default-1428044128830\sessionstore-backups
The file called “recovery” should be there. Open it with notepad.
Now, from your copied stuff on your desktop, use notepad to open the “sessionrestore” file that actually contains the tabs you really wanted to restore. You can right click in notepad and use “select all” to select everything. Then copy all of that text. Erase everything in the “recovery” file, and paste in the stuff you copied.
Now just “crash” firefox again, have this “recovery” file saved with all the good stuff copied into it, and start firefox again. This time the session restore page should be all the stuff you wanted.