can you try downloading the full installer file from http://www.mozilla.org/en-US/firefox/all.html installing it again?

Thank you for giving the crash ID! Unfortunately that one looks like it got corrupted, it's empty :(

If reinstalling Firefox doesn't work, I'm going to give you several steps you can take to try to correct the problem.

Try to start Firefox in Safe mode. This mode disables all extensions, user customizations, hardware acceleration, etc. temporarily for diagnostic and troubleshooting. If Firefox works fine in Safe Mode, then this is likely an add-on issue. Restart Firefox in normal mode, then type "About:addons" (without the quotes) in the address bar. Disable your extensions one by one, restarting Firefox between each one, until you find the trouble maker. Once you do, you can disable that add-on and report the issue to that add-on's developer.

A few other basic trouble shooting things you can try is this: Run all Windows Updates, install all needed service packs, etc.

Update your graphics driver (Firefox uses your graphics card for some rendering, and an out of date graphics card driver can cause problems. https://support.mozilla.org/en-US/kb/how-do-i-upgrade-my-graphics-drivers.

Update all your plugins (Flash, Java, etc.): http://www.mozilla.org/plugincheck/.

Download and Install MalwareBytes Anti-Malware, run a full Scan. http://www.malwarebytes.org/. This helps check that there are no viruses on your computer causing issues. You can uninstall this program after you clean off any infections.

If these don't work, I'll walk you through the steps to completely remove Firefox and reinstall it, which should get it back working. these steps are a bit easier though, so give them a go ;)

Hi Guys! Thanks for your reply's to my problem. I downloaded a newversion of the installer and installed it. It then gave me the same problem again but I got it in to Safe mode. There I Updated all the plugins and afterwords it worked like a dream. :)

It looks like it was a combination of stuff that broke firefox. Acrobat,java and a fualty download :)

Thanks for all your advice!