It sounds like you are not able to update iTunes, nor see your iPad in iTunes anymore. I recommend these steps to help get your iTunes application updating correctly:
If you do not have an active connection to the Internet, or if your Internet security settings are configured to prevent iTunes from communicating with Apple, iTunes will alert you that the update server could not be contacted. Resolve your Internet issues and attempt to update again.
- If you are using Windows, see iTunes for Windows XP: iTunes cannot contact the iPod, iPad, or iPhone software update server and iTunes for Windows: Network Connectivity Tests.
- If you are using Mac OS X, see Mac OS X: Connect to the Internet and troubleshoot your Internet connection.
From: iTunes: How to install the latest version
For your iPad not showing in iTunes I would try either of these articles depending on the computer you are using:
iOS: Device not recognized in iTunes for Windows
iOS: Device not recognized in iTunes for Mac OS X
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I had this very problem on Mac OS. This link fixed it for me - nothing else worked on the Apple site.
The error message said 'iTunes could not contact the iPhone software update server because you’re not connected to the Internet.'
Here’s how: Open ‘System Preferences’, click ‘Network’, select your network interface and click ‘Advanced…’. Switch to the ‘Proxies’ tab and tick the box labelled ‘Auto Proxy Discovery’. Confirm with OK.
Now it works.