声卡驱动有安装么？建议驱动都安装一下[url]http://support1.lenovo.com.cn/lenovo/wsi/Modules/Driverdownload.aspx?SearchType=1&LogicType=1&MachineId=-6685&IsSeachOne=true&IsBackPage=false&typename=IdeaPad+Y450[/url]
