How to fix iPad, iPod touch, iPhone could not be restored − an unknown error occurred (4013) in iTunes (iPad)

Maybe the connection between your computer or iOS device can't be established because of an ongoing process that was taking place on your computer or iOS device has become unresponsive. Unresponsive processes can cause the device couldn't be restored - an unknown error occurred (4013) iTunes error message to appear.

To fix this error restart the computer, and restart your iOS device, too. Then try to restore your iOS device.

Older iTunes versions can definitely be responsible for many errors, including iTunes error 4013. To fix this, and many other errors you may not be aware of that mostly appear due to corrupt, obsolete, or missing files, you need to update iTunes to the latest version. Usually, updates are downloaded installed automatically, however, there are always exceptions to that rule. Sometimes, you need to check for updates manually, through iTunes, or on Apple's website.

To check for updates manually, via iTunes:

1. Open the iTunes app;
2. Click on Help and select Check for updates.
   
   

   
   
   

Or, you can follow the instructions in the video demo, below:

On our devices, there is space reserved for the operating system, and space left for us to manage. However, over time, the system updates require more and more space, leaving less space at our disposal. Since our devices need free storage space, so that the operating system can function as expected, if there isn't enough free space left, the operating system won't be able to update itself, and troubles will follow.

To free up space, and fix this error, you can consider the following options:

• Remove apps you don't use;
• Remove photos you don't need, or that you have backed up elsewhere;
• Remove songs, and videos you don't need, or that are already backed up;
• Remove documents you don't need.
  
  

Note: Feel free to check out the how to free up space guide, for more solutions on how to free up space.

The lightning cable is made of a couple of wires. On both sides, the wires are merged to small plates that connect with the corresponding plates on both your computer and iOS device. If at least one of those plates won't "touch" the corresponding plate on the other side, errors can occur, since your device won't be detected by the computer, and you won't be able to restore it.

A way to ensure a firm connection is to unplug the lightning cable, and plug it back in your iOS device and the computer.

It is possible that malicious software that found its way to your computer's files, especially to the iTunes-related ones, caused this error. Scan your computer for malicious software with an antivirus or anti malware software and remove every single threat, if detected.

Removing the viruses is not enough, as new ones can always infiltrate your computer, if you aren't careful enough. To keep your computer and the data stored on it protected follow the instructions below:

1. Don't open suspicious emails;
2. Don't visit suspicious websites (websites with irresistible and unrealistic offers);
3. Don't download and install programs from websites other than the program developers.
   
   

To learn more about how to protect your computer and how to clean it from viruses and other types of malicious software, feel free to check the easy-to-follow Computer virus protection guide.

Maybe your computer's USB port or iOS device's lightning port (or both) are dirty. Dirt, in any form, can prevent a stable data transfer, since the plates from the USB cable won't connect with the corresponding plates on your computer, or iOS device, which can result in corrupted, incomplete files, as well as error messages, among which is this iTunes error.

This can easily be addressed if you clean the ports of your computer, and iOS device. All you need to do is to grab a tiny cotton swab, sip a small amount of rubbing (isopropyl) alcohol on it and then gently clean the USB and lightning ports. Wait until the alcohol evaporates (usually up to a minute) and then try updating your device again.

Stable internet access is needed for almost every operation you do with your iOS device, including restoring it, because files need to be downloaded from the Apple servers first. Unstable internet connection may result in incorrectly downloaded (corrupt) files, as well as error 4013. Make sure that your internet connection is stable, before you restore your device.

Common solutions to improve your Internet stability include:

1. Get closer to the router with your computer;
2. Keep your router in a central position of your house/apartment;
3. Use an underused router channel;
4. Buy a Wi-Fi signal booster.
   
   

You may also want to restart your router, as it may affect the stability of your Internet connection.

For more tips on improving your Internet connection, feel free to check the guide on fixing slow Internet connection.

If you aren't sure how to address this iTunes error, and where to start from you can always ask professionals for help. Apple's support team is at your disposal, and they will help you diagnose and fix the issue.

You can contact Apple's support staff online, any time, via getsupport.apple.com 

Make sure that you always use genuine and approved accessories for your device, and avoid the fake ones as much as possible, because they cannot establish a proper connection between your computer and iOS device. Although they may look the same from the outside, fake lightning cables can be responsible for many errors in the communication between your computer and iOS device, including iTunes error 4013.

To be able to restore your device, you need to buy a genuine cable. This article on Apple's website reveals how to distinguish between fake and genuine cables, as well as recognize genuine cables.

USB ports are fragile and can easily be damaged if we use too much force when plugging in USB cables in them. The most commonly used USB ports have several four pins, and if one of the pins is damaged, the port won't work.

Maybe the USB port in which the lightning USB cable is plugged in is damaged and the computer cannot detect the mobile device properly. In this case, to fix error 4013, plug the cable in a different USB port. Then, try restoring your iOS device.

By updating your computer's operating system, you will install the latest patches and fix bugs that were present in the previous version. As part of the update, you may fix this error, too.

If you are not sure how to update the operating system, do check out the don't know how to update my device's operating system guide.