edit.. you already answered what I originally posted about.
Since you're using a PC. Do you have any kind of antivirus or firewall setup?
This. From Apple:
"If you have a firewall enabled in your router or computer, make sure that the firewall is not blocking communication between your computer and iOS device. In order to use the built-in firewall option with iTunes on your Mac, follow the directions in this article. For non-Apple firewalls and security software, refer to the developer/manufacturer for assistance.
Note: Mac computers use port 123 to set the date and time automatically. Incorrect date and time on a computer or iOS device can cause issues for connections in general.
If you are unsure if your router has a firewall or if the required ports are open, do the following to help isolate the issue:
Enable Wi-Fi Syncing for additional iOS devices on your network to see if they have the same issue. (See the steps above for info on how to enable Wi-Fi Syncing for these additional devices).
Test your device on a different network. If the device works on another network, the issue most likely exists with your router or network configuration. Contact your router manufacturer or Internet service provider for additional troubleshooting.
If you use another security or firewall software on your computer or router, follow iTunes for Windows: Troubleshooting security software issues, contact the manufacturer, or check the documentation on how to open TCP ports 123 and 3689, as well as UDP ports 123 and 5353."
