Cannot Launch Firefox

Ever since I downloaded a wrong theme for Firefox, I've been unable to launch it. I've uninstalled it, done a search for its files and deleted them and today downloaded and tried to install a later version (0.9.3) but still it will not launch. Instead I get this message: Error launching browser window: XBL binding for browser.

Any suggestions? If I go to regedit to delete some keys, which ones do I delete and exactly how do I go about doing this?

 

James,

Have you deleted the problem extension from the extension folder located here:
< path >\Application Data\Mozilla\Firefox\Profiles\default.xxx\extensions

That should help, but if not, try a new Profile. If Firefox starts, then transfer your data to the new Profile.

Ramona