The "Sis191 Ethernet Contoller" is for wired networks, not wireless communications. Make sure there is nothing under Other Devices. Also, many laptops and netbooks come with a switch to turn off wireless to save battery power, so very carefully check the whole outside of your laptop to make sure you have not just switched it off by accident.
If this is not the problem, please tell me the model of your wireless card if you know it, and use Speccy to send me your motherboard or chipset (same thing) model number. Speccy