Hey there Dan256162,
I understand that you are receiving a specific error code when attempting to connect to the iTunes Store, error 0x80090318. I have an article for you that references this code and links you to another article for troubleshooting to address this issue. Here is the article that references the error code:
iTunes: Possible iTunes Store errors - Apple Support
http://support.apple.com/en-us/HT203174
And here is the linked troubleshooting article that will help you resolve the issue:
Apple software on Windows: May see performance issues and blank iTunes Store - Apple Support
http://support.apple.com/en-us/TS4123
Take care, and thanks for visiting the Apple Support Communities.
Cheers,
Braden