Maybe one of these articles will help?

• http://kb.mozillazine.org/Browser_will_not_start_up#XULRunner_error_after_an_update

• Firefox won't start - find solutions

Download a fresh Firefox copy and save the file to the desktop.

• Firefox 6.0.x: http://www.mozilla.com/en-US/firefox/all.html

• Uninstall your current Firefox version.
• Do not remove personal data when you uninstall the current version.

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

• It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.

Your bookmarks and other profile data are stored elsewhere in the Firefox Profile Folder and won't be affected by a reinstall, but make sure that you do not select to remove personal data if you uninstall Firefox.

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Profile_backup

TY AliceWyman,

The article on "XULRunner error after update" gave me the answer. Playing around w/ some of the solutions posed in the article brought me to the solution. My ZA Internet Security "Clear Virtualization" setting was what was stopping Firefox from starting.

Thank You again, Bovax  :)

Hey, that's great! Thanks for posting back.

Thanks for that info it cured the problem for me.