Hi When you select Restore Previous Session from the default home page

If you had tabs and windows open when you last closed Firefox, the default Firefox home page will have a Restore Previous Session button on it. To get your tabs and windows back, just click it. Restore1 29 - Win Note: If you've set your home page to something other than the default Firefox home page, you can restore the default home page. When you select Restore Previous Session from the History menu

Here's how to get your tabs and windows from a previous session back if you don't use the default Firefox home page:

   Click on the menu button new fx menu on the right side of your toolbar. Select History to expand the drop-down list and choose Restore Previous Session.

   Restore2 29 - Win

After installing an add-on

When a new extension or theme is installed, you must restart Firefox to enable the new add-on. To restart, click Restart Now. All windows and tabs are re-opened when Firefox restarts and installs the new add-on.

Session1 29 - Win

After a software update

To apply any updates to the Firefox application that have been downloaded, you must restart Firefox. To restart, click Restart to Update.

Update Win2

After restarting with add-ons disabled

When you restart with add-ons disabled to troubleshoot Firefox problems, your tabs and windows will be reopened. After a crash

Due to unexpected issues such as problems with a website, software errors, or an accidental loss of power, Firefox may unexpectedly close. In these situations, Firefox can restore the pages that you were visiting when it is restarted. Firefox will automatically restore your previous session, the first time you launch it after a crash.

If Firefox crashes a second time, the Restore Session (i.e. "Well, this is embarrassing") page will appear when you next launch Firefox.

FxCrash-RestoreSession

   To restore your previous session, select the windows or tabs you want to restore and click Restore.
   If Firefox continues to experience errors when windows and tabs are re-opened, you can launch Firefox without restoring these items. Click Start New Session. 

When you've set Firefox to show your windows and tabs from last time

You can set Firefox to always show your windows and tabs from your previous session each time you start Firefox. To change your Firefox startup settings, see Configuring session restore, below. Configuring session restore

By default, when Firefox starts, a single window is opened, displaying your specified home page. If you wish, you can configure Firefox to open all windows and tabs from your previous session:

Session2 29 - Win

   Click the menu button New Fx Menu and choose Options
   .
   Select the General panel.
   From the When Firefox starts drop-down, select Show my windows and tabs from last time.
   Click OK to close the Options window .

You can make a backup copy of the previous.js file and the other files in the sessionstore-backups folder elsewhere. You can copy the previous.js file as sessionstore.js to the main profile folder to replace the current sessionstore.js file. That should allow to restore the session. You may have to check History > Recently Closed Tabs/Windows.

About sessionstore: https://addons.mozilla.org/firefox/addon/about-sessionstore/

Let me elaborate. This does not show the option to restore the previous window,so I have to do it manually by tinkering around with filenames and what not.

Cor-el I tried what you suggested, it didn 't work out. Any alternatives?

You can open the previous.js file in a Firefox tab.

Open the Web Console (Firefox/Tools > Web Developer) and paste this code in the command line and press the Enter/Return key:

eval("ss = "+document.body.innerHTML.replace("<pre>","").replace("</pre>",""));
sd='';
for (var i = 0; i < ss.windows[0].tabs.length; i++) {
 var ent = ss.windows[0].tabs[i].entries;
 var last = ent[ent.length-1];
 sd+="<a href="+last.url+">"+last.url+"</a><br />";
}
document.body.innerHTML=sd;

Hi ZoravarSingh, I'm not sure whether you found this in your reading, but there's a fine point of timing on the file swap cor-el mentioned. Make sure Firefox is fully closed and has created the new sessionstore.js file before renaming a copy of previous.js to sessionstore.js and dropping it into your profile folder, replacing the sessionstore.js that Firefox created at shutdown. Then at startup, if Firefox is set to restore your previous session automatically, it should use your substitute sessionstore.js. If it is set to start up with your home page, you'll need to use History > Restore Previous Session to have Firefox read the substitute file.