What is the startup setting?

Tabs are restored with this setting:

• Tools > Options > General > Startup: When Firefox Starts: Show my windows and tabs from last time

It is possible that there is a problem with the files sessionstore.js and sessionstore.bak in the Firefox Profile Folder.

Delete the sessionstore.js file and possible sessionstore-##.js files with a number and sessionstore.bak in the Firefox Profile Folder.

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost, so you will have to create them again (make a note or bookmark them).

• http://kb.mozillazine.org/Multiple_profile_files_created

Setting is at : Show my homepage only

Firefox may not be closing properly if the previous session is restored.

Try to use "Firefox/File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit") to close Firefox if you are currently doing that by clicking the close X on the title bar.

See Also

• "Hang at exit": http://kb.mozillazine.org/Firefox_hangs
• "Firefox hangs when you quit it": https://support.mozilla.org/kb/Firefox+hangs

well .......right ........... I think you are telling my that I need to go into "Profiles" via that web link to 'MozillaZine' which I'm not signed in to. But....... that there may be multiple copies of cookie files causing the browser to hang or causing past session tabs to appear when restart initiated. You have gone beyond me with the X out option or doing something instead of xing out. Is it possible to go into about;config and remove all duplicate profile files without having to save or loose a bunch of stuff ?

Ok : found profile etc : you want me to delete this file : is that correct ? sessionstore ........ Jscript file ... 37Kb ......that one ?

I'm getting an error message when I try to open that file ; does that mean it's corrupt ?

also I'm not finding any duplicate files in Profile file

where to you find or type this in order to close firefox browser ? Firefox/File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit

I tried the following and it didn't work :

Previous session not correctly closed

To get your tabs and windows back from a previous session, you should close Firefox from the menu: At the top of the Firefox window, click on the Firefox button (File menu in Windows XP) and then click Exit. If you close each window or tab, only the tabs in the final window that you close are available when you restart Firefox. Settings may be incorrect

For other session restore problems, you may need to make corrections to your Firefox settings:

   At the top of the Firefox window, click on the Firefox button (Tools menu in Windows XP) and then click Options
   Select the Privacy panel and make sure Firefox will: is set to either Remember history or Use custom settings for history.
       If Firefox will: is set to Use custom settings for history then make sure that Permanent Private Browsing mode is not selected.
       If Firefox will: is set to Use custom settings for history and Clear history when Firefox closes is selected, then click the Settings button and make sure that Browsing History is not selected. 
   Click OK to close the Options window

correction : this is what I tried : Privacy issues

Session Restore may keep you logged in to sites that you were logged into before you closed Firefox. If someone else used your computer after you, they could access your account on these sites. If this is a concern then you should not configure Firefox to open all windows and tabs from your previous session.

You may also wish to disable the Session Restore crash recovery feature which is enabled by default. This will prevent restoring a previous session when Firefox is opened after an unexpected close or software crash:

   In the Location bar, type about:config and press Enter.
       The about:config "This might void your warranty!" warning page may appear. Click I'll be careful, I promise!, to continue to the about:config page. 
   In the Search box at the top, type browser.sessionstore.resume_from_crash.
   In the resulting grid, double-click on browser.sessionstore.resume_from_crash to set it to false.

I'm finding a lot about restoring tabs from previous session but not much about getting rid of tabs that won't go away after restart.

Some files like the .js files in the Firefox Profile Folder are text files that you can open in a text editor for inspection.
Others are binary files and can either not opened or in case of sqlite file with a program or Firefox extensions like SQLite Manager that can handle such files, but that is usually not necessary.
If files are corrupted then a quick check is to rename file or move the file to a different location to see if that helps.

It is possible that there is a problem with the files sessionstore.js and sessionstore.bak in the Firefox Profile Folder if tabs from a previous session are loaded on the next start.

Delete the sessionstore.js file and possible sessionstore-##.js files with a number and sessionstore.bak in the Firefox Profile Folder.

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost, so you will have to create them again (make a note or bookmark them).

• http://kb.mozillazine.org/Multiple_profile_files_created

You can use this button to go to the Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder