Download the driver for your PC and your OS from the makers site. That can be the maker of the laptop (say, HP or Dell or Lenovo or Asus) or - if it's a desktop with a separate WiFi-card or dongle - the maker of that card or dongle.
Then install it the proper way (what the proper way depends on the file type of the downloaded file).
I installed Windows 8 recently but there is no option to connect wireless devices. The WiFi option is disabled. Don't know which driver I want to use. It showing a problem network cable is not properly plugged in or may be broken. But I don't use any lan cables. How to solve this problem guide me please.