windows 8.1 automatically install the drivers for me.
i tried the web site LB link web site download the drivers but won't install. i had to disable driver signature enforcement. then the drivers work.
i also tried
www.realtek.com download drivers from there also. still at 150Mbps
RTL8191SU Realtek web site does say it runs at 300Mbps. must be something wrong with the adapter or its fake