Try any or all of the following:

• Install Firefox 22.0 because 24 still has bugs and security issues
• Run an full anti-virus scan
• Scan for bad registries (I recommend using CCleaner)
• Defragment your computer's hard drive
• Delete all temporary memory and cache
• Remove unwanted/unused programs
• Remove unused Firefox extensions
• Update all Firefox plugins

I would disagree with using any registry cleaner.

• http://www.howtogeek.com/57637/what-you-saidhave-registry-cleaners-helped-your-computer-ever/

As they may delete essential pieces of configuration and may render your computer unuseable.

I would though try disabling firefox's gfx (hardware acceleration) and try safe mode.

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Also aurora is stable enough for the regular user though you could try the release version.

@Waka_Flocka_Flame

Cleaning registries manually can cause damage to your computer, but cleaning registries using a registry cleaning program like CCleaner is very important to your computer's health.

Bad registries can prevent your computer from booting properly, so removing those registries in important. Bad registries can be caused by a number of things:

• Missing Shared DLLs
• Unused File Extensions
• ActiveX and Class Issues
• Type Libraries
• Applications
• Fonts
• Application Paths
• Help Files
• Installers
• Obsolete Software
• Start Menu Folders
• MUI Cache
• Sound Events
• Windows Services
• And More...

Personally, I run CCleaner before a shutdown my computer.

I highly recommend scanning, to increase your computer's performance and to keep it fully functional.

NOTE: As with any software, use caution when using it and only download it from a trustworthy source.

A possible cause that has been reported is a problem with downloadable fonts in combination with having a lot fonts installed on the computer.

As a test you can try to disable downloadable fonts by setting the gfx.downloadable_fonts.enabled pref to false on the about:config page.

• http://kb.mozillazine.org/about:config

Note that this causes problems on websites that use a special to represent icons.

See e.g.: https://github.com/styleguide/css/7.0