Q: 3914 error, along with Diagnostics saying that I don't have a secure link to the iTunes Store.

Try reseting through itunes

Have you looked at the previous discussions listed on the right side of this page under the heading "More Like This"?

Also try:

- Powering off and then back on your router.

- iTunes for Windows: iTunes cannot contact the iPhone, iPad, or iPod software update server

- Change the DNS to either Google's or Open DNS servers

Public DNS — Google Developers

OpenDNS IP Addresses

- For one user uninstalling/reinstalling iTunes resolved the problem

- Try on another computer/network

- Wait if it is an Apple problem