FIRST STEP

To fix the WIFI problem, you need to change the power management settings for wifi network adapeter

• Go to Control Panel > Device Manager 
• Under "Network Adapters" right click and open the properties for your wireless adapter 
• Under the "power management" tab, uncheck " Allow the computer to turn off this device to save power" 

Reboot! 

If it continues to do not work, try this

SECOND STEP

Change your DNS, view this video guide.