As the title states, how do I reset FireFox to its original state?
Sorry, it's "Troubleshooting Information".
Troubleshoot and diagnose Firefox problems
Use the Troubleshooting Information page to help fix Firefox issues
I use MozBackup - very simple to restore Firefox. In Firefox itself, go to Help --- Troubleshoot Information and you will see a Reset button on upper-right (like here ---> http://www.youtube.com/watch?v=c80FrKNscEg).
If you mean with no extensions or addons etc just create a new profile. To do this press the Win key and R at the same time to get the run box up and type in it - firefox.exe -p to open the profile manager.
Type about:support into the address bar and press Enter. Then click on the Reset Firefox button.
It will save a copy of your profile to your hard drive in case you change your mind. Then it will restart itself.
After it has restarted you will notice everything is gone EXCEPT your bookmarks. They will still be there.
How do I reset Firefox to its default state?
1) At the top of the Firefox window, click the Firefox button, go over to the Help sub-menu
and select Troubleshooting Information.
2) 2.Click the Reset Firefox button in the upper-right corner of the Troubleshooting Information page.