If you launch Firefox, go to file menu, choose 'Open File...', then navigate to and open the ieview.xpi file.
Firefox should recognize that this is a Firefox extension; unless something in your Firefox "about:config" has been modified, Firefox will correctly install it for you. You might need to restart Firefox.
Re: IEview
If you launch Firefox, go to file menu, choose 'Open File...', then navigate to and open the ieview.xpi file.
Firefox should recognize that this is a Firefox extension; unless something in your Firefox "about:config" has been modified, Firefox will correctly install it for you. You might need to restart Firefox.