修改用户配置文件userChrome.css， 增加如下内容：
/* Make menus XP style */
menupopup, popup {
border: 1px solid ThreeDShadow !important;
-moz-border-left-colors: ThreeDShadow !important;
-moz-border-top-colors: ThreeDShadow !important;
-moz-border-right-colors: ThreeDShadow !important;
-moz-border-bottom-colors: ThreeDShadow !important;
padding: 2px !important;
background-color: Menu !important;
}
menubar > menu {
border: 1px solid transparent !important;
padding: 2px 5px 2px 7px !important;
margin: 0 !important;
}
menubar > menu[_moz-menuactive="true"] {
background-color : Highlight !important;
color: HighlightText !important;
}