Assume a Windows 7 system (probably whatever home version comes with the machine), with the latest OS patches, latest IE and latest Firefox. Also assume that the user uses only Firefox for browsing, never IE, and that uninstalling IE is impossible or impractical.
In the context of "safer" usage while browsing, is it sufficient to take steps to harden Firefox, or do I also need to worry about IE?
The underlying question is: Assuming a "Joe Sixpack" home user, are there attacks that target IE that can be triggered from actions taken by a user who doesn't knowingly start IE for web browsing? (And are they mitigated by hardening such as suggested in documents like this one.)