If you’re having problems with Firefox crashing on your PC – the most likely culprit is Flash.
You’ll need the latest version of the Adobe’s Flash Plugin which you can find here:
http://get.adobe.com/flashplayer/
If the install fails using the above link the most likely reason is that your proxy/firewall is stopping the online installer from downloading the required install files.
In that case try downloading and installing from here (hopefully you have local admin privileges on your PC):
http://download.macromedia.com/pub/flashplayer/current/support/install_flash_player.exe
