No Internet connection after upgrade to Windows 10

Solution 1:

Make sure the IPv4 and IPv6 protocols are enabled:

• Go to Advanced Network settings
• Go to Network and Sharing Centre

• Go to Change Adapter Settings

  

• Select Properties for the Wifi Adapter (right-click your connection):

  

• Make sure the IPv4 and IPv6 protocols are selected

  

I also couldn't connect to internet after upgrading and found that these had been disabled. Once enabled you should be able to connect.

Solution 2:

After sleepless weekend got rid of this problem. It is Bitdefender TS in my case. Uninstalled it and Internet came back in a flash. Also updated all drivers for my Mobo Gigabyte D3H B85M from official site to Windows 10. Re-install latest version of Bitdefender TS. All fine now. Thank God.