Hi try stopping it in the Task Manager (Ctrl+Shift+Esc) > Applications tab, by selecting Firefox then clicking the button at the bottom. You could also try stopping any Firefox Processes in the Processes tab - there's probably more than one. If successful, I would then restart your PC - click on Restart in the Start Button, then after it's settled, try Fx again.

If your question is resolved by this or another answer, please take a minute to let us know. Thank you!

I'm afraid I've already done that. Interestingly, Firefox didn't show as running so there was nothing to close. I then shut down the laptop, opened it up and got the same "do you want to restore previous session" message. The box in setting to retore each time you start up is unchecked so that's not the cause. Thank you for the suggestion though.

OK, since it appears not to be actually running, try a Clean Reinstall; this means you remove your Firefox program files and then reinstall Firefox. This process does not remove your Firefox profile data (such as bookmarks and passwords), since that information is stored in a different location. With Firefox closed, use another browser to download Firefox from https://www.mozilla.org/en-US/firefox/all/ and save the file to somewhere convenient on your computer.

Now delete the Firefox installation folder which should be in one of the following locations -

C:\Program Files\Mozilla Firefox C:\Program Files (x86)\Mozilla Firefox

You can now double click the file you previously downloaded to install Firefox.

If that doesn't work, I'm going to suggest you try Refresh, but since it can very occasionally cause issues of its own - to be on the safe side, before you do it, I would backup your bookmarks: Open bookmarks > Show All Bookmarks > Import and Backup > Backup. Or, Export Bookmarks to HTML, and save them to somewhere convenient on your computer. Note that Backup will overwrite any existing bookmarks when you restore them. For extra safety, I'd suggest making both a Backup - which creates a JSON file, and an HTML file. You can instead backup all your data by copying your Profile, but this requires some technical expertise - Back up and restore information in Firefox profiles.

The Refresh feature (called "Reset" in older Firefox versions) can fix many issues by restoring Firefox to its factory default state while saving your bookmarks, history, passwords, cookies, and other essential information.

Note: When you use this feature, you will lose any extensions, toolbar customizations, and some preferences so you might want to make a note of any extensions you have. See the Refresh Firefox - reset add-ons and settings article for more information.

To Refresh Firefox:

1. Open the Troubleshooting Information page using one of these methods:
   • Click the menu button , click help and select Troubleshooting Information. A new tab containing your troubleshooting information should open.
   • If you're unable to access the Help menu, type about:support in your address bar to bring up the Troubleshooting Information page.
2. At the top right corner of the page, you should see a button that says "Refresh Firefox" ("Reset Firefox" in older Firefox versions). Click on it.
3. Firefox will close. After the refresh process is completed, Firefox will show a window with the information that is imported.
4. Click Finish and Firefox will reopen.

Did this fix the problem? Please report back to us!

Thank you.

Thank you again Scribe. I did this last night and unfortunately it didn't help either.  :(

Are you using "Clear history when Firefox closes" to clear any session data?

Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox title bar.

• "3-bar" menu button -> Exit (Power button)
• Windows: File -> Exit
• Mac: Firefox -> Quit Firefox
• Linux: File -> Quit

You can create a new profile to test if your current profile is causing the problem. Do not make any modifications until you have tested this profile.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

Thank you Cor-el. I'm not using the clear history option. I did notice it on the settings but thought that would mean I'd have to input all logins every single time I visited a page so avoided it. Should I have that ticked? If so, that might cure the problem.

If it doesn't, then I'll try a new profile as you suggest. Thank you.

No, there is no need to use "Clear history when Firefox closes". If you would clear cookies that way then special "remember me " cookies will be removed as well and you need to login every time. I only suggested it that there can possibly issues this feature is enabled.

• clearing "Cookies" will remove all selected cookies including cookies with an "Allow" exception you may want to keep
• clearing "Site Preferences" clears exceptions for cookies, images, pop-up windows, and software installation and exception for password and other website specific data

I've actually sorted it out but by drastic means! As it's a new laptop and I have everything backed up, I decided to do a restore. Everything was wiped off and I installed Firefox again and voila! Problem solved! I think there must have been something lingering around the computer that was causing the issue and with the restore this seems to have cleaned it up.

Thank you so much to everybody who helped by answering my question. I'm very grateful.

do you turn off your computer before you exit firefox? firefox take few seconds before it completly exit.

FFus3r said

do you turn off your computer before you exit firefox? firefox take few seconds before it completly exit.

No I always close apps before shutting down