Microsoft® Windows Media Player Firefox Plugin File: np-mswmp.dll Version: 1.0.0.8 np-mswmp MIME Type Description Suffixes Enabled application/x-ms-wmp np-mswmp * Yes application/asx * Yes video/x-ms-asf-plugin * Yes application/x-mplayer2 * Yes video/x-ms-asf asf,asx,* Yes video/x-ms-wm wm,* Yes audio/x-ms-wma wma,* Yes audio/x-ms-wax wax,* Yes video/x-ms-wmv wmv,* Yes video/x-ms-wvx wvx,* YesThere is an interesting thread here about this topic (a few years old, don't know if it's still relevant): http://forums.mozillazine.org/viewtopic.php?p=2200102