I have just updated my itunes and now i can't get onto the itunes store on my pc

I am trying everthing that the help support is showing me and so far nothing is working I getting very mad

Is there anyone who can help me please.

This error keeps coming up " ITunes Could Not Connect to Itunes store, unknown error occurred (0x80090318)".

Does anyone know what this means. I am connect to the internet and I was connecting fine to the itunes store until i upgraded my itunes for my iphone 5c reasones.