how fix error 3194

Try the troubleshooting on this page : http://support.apple.com/kb/ts4451

Make sure you have the current version of iTunes. Restart your computer and try again.

Have you made any unauthorised changes to your iPad's iOS version e.g. jailbroken it, trying to downgrade the iOS version ?

Have you made any modifications to the version of iOS that you have installed on your iPad e.g. have you jailbroken your iPad, or have you tried to downgrade the iOS version by trying to install a previous version ?

teste

Downgrading the iOS version isn't supported by Apple.

You can't downgrade - is that what you are trying to do when you are getting the 3194 error ?

Error 3194:

This device isn't eligible for the requested build

It means that Apple has stopped signing the version of iOS that you have, try downloading the latest iOS version, then try Restore again.