You will agree with me that there are Add-ons that your computer may install without requesting for your permission (due to your system settings though). To fix this problem, follow this guide:

==> Go to your Mozilla Firefox Homepage
==> Click on Open Menu
==> Click Add-ons manager
==> Click on Extension. Here you will see list of programs your Mozilla install without requesting your permission ( examples: Alexa Toolbar, Avast Online security, adblocker). Take your time carefully to look for those programs that are less important to you and click Remove.
==> Your Firefox will prompt you to Restart
==> Click Restart Now.

Your Mozilla should restart immediately. There you go! You are now half way done. Follow the next steps:

==> Go to your Windows Menu
==> Click Computer
==> Click Uninstall or Change programs
==> Search program and features.
==> Uninstall the programs that you don’t need or probably installed without your permission.
==> Search for Java and remove the ones that are less important (of no use) to you.
==> Restart your computer.

Note: If Firefox is open but won't respond to any of your actions, then this is a hang, not a crash:

When Firefox hangs, it stops responding to your clicks and keystrokes and doesn't seem to be doing anything. Also, a "(Not Responding)" label is displayed in the title bar and the mouse becomes a spinning wait cursor when it's over the Firefox window. This article gives you solutions to Firefox hangs depending on when they happen.

In most cases, crashing or browser not responding may be due to poor or bad network. In the case of bad network, just disconnect Wi-Fi or Modem and reconnect again.

This works well for me and I am sure it will definitely work for you as well. Anyway, give it a try and let me know what you think. http://www.trendymediablog.com/2014/10/mozilla-firefox-crashes-how-to-fix-it.html

Thanxx alot

You are welcome

lordnammy:
Thanxx alot