- Powering off and then back on your router.
- Change the DNS to either Google's or Open DNS servers
- For one user uninstalling/reinstalling iTunes resolved the problem
- Try on another computer/network
- Wait if it is an Apple problem
is for what yo do to yur computer/networ/router
This does not apple to a 1G or 2G iPod
If you can access your device's settings menu and connect to Wi-Fi, install the latest version of iOS over Wi-Fi using Settings > General > Software Update. If your device is locked with a forgotten passcode or in recovery mode, you will need iTunes to restore the device.
If one of the alert messages above appears when you try to update or restore your iOS device, connect to the Internet with your preferred web browser, and access the iTunes Store.