When I open itunes, itunes could not connect to the itunes store with unknown error code Ox80090318 although I am connected to internet

My Windows 8.1 laptop is connected with internet. However, when I open itunes, I got the message:

itunes could not connect to the itunes store. An unknow error occurred (Ox80090318). Make sure your network connection is active and try again.

No matter how I try, the message keeps on coming back and itunes will not connect itune store.

Can someone tell me why please.