That is why you should be cautious with using System Restore.

What happened is that Windows has restored the sessionstore.js file and probably other .js and .ini files in the Firefox profile folder.

Restoring the sessionstore.js file has caused that old session to reappear.

I don't know if you have access to more recent versions via "Properties > Previous Versions" in the right-click context menu of the file.

• http://windows.microsoft.com/en-US/windows7/Previous-versions-of-files-frequently-asked-questions

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

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Next time you decide to do a Session Restore make sure to backup your Firefox profile folder.

• http://kb.mozillazine.org/Profile_backup
• https://support.mozilla.org/kb/Backing+up+your+information

I think you asking how to configure Firefox so that Windows' system restore feature will NOT affect your Firefox settings? That might be possible if you move your Firefox profile folder to a location not affected/protected by system restore, but I don't know enough about what Windows backs up to confidently direct you to a particular location.

cor-el, I do system restore only because Blue Screen of Dead, appears a lot, so I need to be sure of security of my session data, then I power down my PC (BSOD appears on power on). I can't make backups every day before power off, because it will save a problem, which cause BSOD, so I need to prevent FF to recovery it's data. Therefore my question is "how can I do this?".

jscher2000, yes, I need that you said.

You can consider to bookmark all open tabs to a bookmarks folder.

Did you check the Windows Event log for details about the cause of these BSOD occurrences?

If BSOD occurs using Firefox, usually it is a graphics driver incompatibility. Make sure to disable Firefox's use of hardware acceleration.

"3-bar" menu button (or Tools menu) > Options > Advanced

On the "General" mini-tab, uncheck the box for "Use hardware acceleration when available"

This takes effect the next time you exit and start Firefox up again.

cor-el, Some hardware problem. Don't have cash to upgrade computer for 3 years, so, need to another hack to not to recovery tabs. "You can consider to bookmark all open tabs to a bookmarks folder." - what does it mean?

jscher2000, no, there is no FF cause of it. As I said, I used Opera earlier, there I have the same BSOD, but Opera doesn't recover my tabs/bookmarks, even if it's settings folder is in AppData too.

This article mentions creating a profile in a custom location and restoring a backup of your current profile to it: Back up and restore information in Firefox profiles.

As I mentioned before, I don't know the best place to put your profile folder to hide it from Windows' system restore feature, but you could try creating a new folder:

C:\MyFirefox\

and put it in there as a subfolder.

I think it's worth a try.

But why Opera is recovery-safe with its settings folder in AppData, but FF not? Maybe there is some other reason?

Firefox's session history file is a .js file. Maybe Windows has a special interest in .js files???

Google says: "System Restore in Win7 removes all *.js (javascript) files after the restore-to date!" - so, maybe you are right. So what should I do, if settings of FF stores in .js files? :0

I don't think there is a way to modify Firefox not to use the .js file extension. What is the last moment where you could safely make a backup? Perhaps you can get a Firefox extension or external program to keep an eye on your settings folder and make backups in a safe location.

The last moment was then I used Opera, not FF :(

The Session Manager extension has options to (1) create a backup when you exit Firefox, and (2) locate it in a different folder. I haven't tested it, but might be handy for you.

• https://addons.mozilla.org/firefox/addon/session-manager/
• http://sessionmanager.mozdev.org/options.html#advanced ("allows the user to override the default location for storing saved sessions")

I already use it

You already use Session Manager? Can you find the options to save backups at shutdown outside your profile folder?

Adjusted new folder. Will check it on next system crash. Thanks.