You may encounter 3194 error when you attempt to downgrade iOS4 to 3.
1.
3.
This error is occurs because your PC is unable to restore the old version iPhone 3.
1.
3 firmware as it tries to run the downgrading process from iOS 4.
This problem can occur to any type or computer model and is linked to the setbacks of iTunes and the files it uses to restore the iPod or iPhone.
It may also be the case if you have issues in your registry causing this error to appear.
What Causes Error 3194? The typical error message that would be displayed on your screen is in this format:

"The iPhone "Tommy's iPhone" could not be restored.
An unknown error occurred (3194).
"

The main cause of this problem is the fact that Apple now signs the firmware and users cannot do any upgrade or downgrade if they use a firmware that Apple has not signed off on.
This issue may be addressed if you use an older firmware signed by Apple, however, this resolution may not work every time.
To downgrade iOS 4 to OS 3.
1.
3, you may apply these steps.
How To Fix Error 3194 The first thing to do is to replace the "Hosts" file of Windows that would incorporate Apple.
com.
To perform this task, you have to locate the path "c:windowssystem32driversetc".
After that, look for the "hosts" file in notepad format.
This can be done by pressing "Open With" and then choosing "Notepad" as you right click the file.
Once opened in notepad, you have to type "74.
208.
10.
249gs.
apple.
com" at the bottom of the document.
After that, you have to make sure the connection of your iPhone device to iTunes is in recovery mode.
To be able to do this, start by switching off your device.
Then on the handset, select the "Home" button and plug the USB cable.
As soon as you successfully connect the USB cable, it will boot up and you will find the message "Connect To iTunes" shown on your screen.
After this, you have to restore your iPhone or iPod.
You can begin doing this by starting your iTunes.
Then you will see that your iPod/iPhone Touch will be detected in recovery mode.
Now, click the "SHIFT" key for users of Windows while also pressing the "ALT" key, however if you are a Mac user you must also press on the "Restore" button.
After that, select OS 3.
1.
3.
This method will enable you to use this version on your iTouch device.
Another way to resolve this error is to run a registry cleaning program in your system.
The registry is one of the potential reasons why errors like 3194 are triggered.
The "registry" is a central database that records important files, information, settings and options.
In order for Windows to load up and run programs, it has to read the required files it needs to perform tasks through this database.
Unfortunately, the registry oftentimes gets corrupted, damaged, infected, or clogged up making your Windows not able to read the necessary files properly.
As this happens, your PC's operation will slow down and Windows will not correctly load the programs.
To eliminate this issue, you have to download and run a registry cleaner tool which will scan through your system and fix all the errors inside.
One highly recommended tool is the "Frontline Registry Cleaner", a widely used software that has proven efficacy in fixing errors and problems on your computer.