This tutorial explains how to fix the Error 3194 - This device isn't eligible for the requested build displayed when you connect your iPhone, iPad or iPad Touch to iTunes. This error occurs when iTunes is unable to contact Apple's update server.
The first step is to check if your system is running the latest version of iTunes. Disconnect your device, launch iTunes, click on the Help menu > Check for updates.
If you are unable to update iTunes then check if the hosts file is preventing your PC or Mac from contacting Apple's server. If you are running Mac OS X then go to private/etc./hosts. In Windows the hosts file is located here C:\windows\system32\drivers\etc\, but don't forget to enable the display of files and extensions first or else the file will remain invisible. Open the hosts file (administrator rights required) and search for entries containing the following address: gs.apple.com. Delete if found, save the hosts file and restart your PC or Mac before updating iTunes again.
Another solution is to temporarily disable your antivirus or firewall software during the time required to update iTunes to avoid any conflicts.