My macbook pro won't connect to itunes store or update

My macbook pro no longer connects to the itunes store. itunes still works and I can access my library, etc. but not to the store.

I've found numerous answers to this saying I'd have to update the software, etc.

It's been a while since the last update of ANYTHING; probably a year + , but whenever I try to install an update after it resets it does nothing - I've tried to install the updates about a dozen times today alone.

Does anyone know how I can get it to update?