Q: the iphone could not be restored unknown error occurred 3194

See: Resolve iOS update and restore errors in iTunes - Apple Support

Then see this one: If you see Error 3194, Error 17, or 'This device isn't eligible for the requested build' in iTunes - Apple Support

Then the next thing to do would be to Contact Apple Support. Or just go straight to the Genius Bar. Whichever is easier.

What version of iOS are you trying to install. Sounds like you are trying to put the wrong version on the device and have caused the error. Is the device jailbroken?

ChrisJ4203 wrote:

 

What version of iOS are you trying to install. Sounds like you are trying to put the wrong version on the device and have caused the error. Is the device jailbroken?

Good point. Didn't think of that

(1) make sure you're running the latest version of iTunes

(2) If you already followed all the instructions (all of them), and you're still having problems, you can either use a friends computer, or take it to a Genius Bar.

I don't know why it is happening. You would probably get better answers if you post in the iTunes forum. Some of the people here (like myself) don't know much about iTunes but more about the iPhone. I've given you all the answers I can.