If you purchased full Hystou HTPC with OpenELECT XBMC installed already, we may already install all drivers including wifi driver for you, so you only need to find the wifi signal and connect, here is picture guide:
Step 1. Turn on the mini pc and go to xbmc screen, click SYSTEM==>OpenELEC
Step 2. Click Connections, find your wifi router address, input your wifi name and password to connect
After connect succesfully, you can find the addons you like and install directly online, in the future when you start the mini pc, it will auto connect to the WiFi you set this time, when you need to make change, just start from step 1 one more time.