Can't open mozilla.

Yeah just change your background and youll be good to go

What about reinstalling the browser

Still same problem.

Try ending all Mozilla processes then uninstall it from control panel make sure everything is uninstalled then install again

Make sure that all traces of FF is removed before reinstalling

Tried opening firefox and google it?

Edit: Just realized this was 3 weeks old oops

Try reinstalling it, a file must of been removed.

tried several times.