Internet Explorer version 5.1 ; 5.1.4 ; 5.1.5 ; 5.1.6 and 5.1.7 requires Mac OS 8.0 or higher . Internet Explorer version 5.1 ; 5.1.4 ; 5.1.5 ; 5.1.6 and 5.1.7 requires Mac OS 8.0 or higher or Mac OS 7.6.1 with Appearance Manager .