Prevent items from opening the iTunes Store
When an item is selected in the iTunes window, you can click the link next to the item to view it in the iTunes Store. You can prevent the links from appearing if, for example, you want to restrict access to the store.
Hide links to the iTunes Store
Choose iTunes > Preferences.
Select “Disable: iTunes Store.”
To allow access to iTunes U when the iTunes Store is disabled, select “Allow access to iTunes U.”
To prevent unauthorized changes, click the lock at the bottom of the preferences pane.