The iTunes error 3600 can come up when you try to restore or update an Apple handheld device like iPhone. When this issue shows up, then the iTunes software becomes unusable. The entire error message that you get when this comes up is as follows – “The “iPhone” could not be updated (restored). An unknown error occurred”.

The main causes for encountering this issue are an outdated Operating System or an outdated iTunes application. Further, if the USB, Lightning cable or port gets damaged somehow, then you might encounter this glitch. Moreover, if the firewall blocks the connection to the Apple server, then also this issue can crop up. 

So, if you are facing this 3600 error on iTunes, you can refer to this article as a complete troubleshooting guide. Here, we have listed all the possible fixes to resolve this issue in a simple manner. 

So, go through this article and apply the fixes to get rid of this problem quickly.

Solutions to Resolve iTunes Error 3600

In this section of the article, you will get to know a number of methods that will help you to get rid of the iTunes error 3600.

Method 1: Inspect the Lightning or USB Cable and Port

You can get this error if either the USB, Lightning cable or port has got damaged somehow. Now, the only solution to resolve this issue is to check the Lightning, USB port and cable. In order to do that, follow the steps underneath.

• First, if the Lightning cable of the iPhone is attached to the computer, then remove it from the device.
• After that, carefully check the outer layer of the cable for any puncture. Now, if there is any kind of slashing on the outer cladding of the Lightning cable, then simply replace it with a new one.
• If the cable does not have any external damages, then inspect the Lightning and the USB port of the iPhone and computer respectively. 
• Next, if you see any foreign particles within the ports, then clean them thoroughly with a lint-free cloth or a cotton swab.
• After that, insert the Lightning cable into the USB port of the computer and see if this process resolves the problem or not.

Method 2: Start the Computer and iPhone Once Again

Sometimes, due to some internal problem with both the iPhone and the computer, this issue might appear. The best answer to resolve this problem is to restart both the iPhone and the computer. Here are the steps that you can follow.

• First, on the computer, press the ‘Windows Logo’. This will launch the ‘Start’ menu.
• Next, from that menu, choose the ‘Power’ icon to open the popup list. Now, from that list, locate the ‘Restart’ option.
• As soon as you click on that option, the computer will instantly initiate the next startup process.
• The restart process of the iPhone is present on the following substeps.
  • First, tap and hold the ‘Power’ then ‘Volume Down’ button until the ‘Slide to Turn Off’ message appears at the bottom of the screen.
  • Next, drag the slider from the left to right edge of the screen to completely shut the iPhone off.
  • At last, press the ‘Power’ button of the iPhone and keep it pressed until you see the Apple Logo on the screen.

Method 3: Set the Settings of the Network on iPhone Once Again

If the network settings of the iPhone are not configured correctly, then you can face this issue. The correct solution to fix this error is to reset the network settings of the iPhone. For that to happen, you will have to follow the steps below.

• First, unlock the iPhone and then locate and choose the ‘Settings’ application. As soon as you do that, a new window with the heading ‘Settings’ will come up.
• In that window, scroll down a bit and then choose the ‘General’ option. This action will launch a new page with the name ‘General’.
• Inside that page, go to the bottom of the screen and then choose the ‘Reset’ option. At this moment, another page with the heading ‘Reset’ will come up.
• Within that page, locate and then choose the ‘Reset Network Settings’ option. If you get a prompt, input the passcode.
• Next, at the bottom of the screen, you will see a popup window, in it, choose the ‘Reset Network settings’ in red color.
• As soon as you do that, the iPhone will begin to reset its network.
• Lastly, check to see if this issue gets fixed or not.

Method 4: Disable the Windows Defender Firewall 

If the Windows Defender Firewall is on, then it can interfere with the connection to the Apple server, which can disrupt either the restore or the update process. The solution to resolve this issue is to deactivate the Firewall feature. To do that, follow the steps below.

• First, press the ‘Windows + R’ keys simultaneously to open the ‘Run’ dialog box. Inside that dialog box, type in the text ‘control panel’ on the blank area beside the label ‘Open:’.Next, tap on the ‘Enter’ key.
• Now, a new window with the title ‘Control Panel’ will come up. Inside that window, there will be all the setting categories for the computer, which you can adjust at your will.
• Next, from that window, choose the ‘System and Security’ option. This action will open a new page with the name ‘System and Security’.
• Within that page, locate and then choose the ‘Windows Firewall’ option. Now, another new page will appear, in it, navigate to the left panel. Then, choose the ‘Turn Windows Defender Firewall on or off’.
• Now, a new page having the title ‘Customize Settings’ will come up. 
• Inside this page, under the two sections ‘Private network settings’ and ‘Public network settings’, choose the ‘Turn off Windows Defender Firewall (not recommended)’ radio button respectively.
• At last, to save this alteration, click on the ‘OK’ button and see if this issue persists or not.

Method 5: Update the iTunes Application

If the iTunes application is not up to date, then there is a chance for you to face this issue. The effective answer to resolve this issue is to update the iTunes software. The steps to do that are as follows:

• First, start the computer and then find and double-click on the iTunes software.
• When the iTunes application launches, go to the menu bar and select the ‘Help’ option. 
• Now, a drop-down list will come up, in it, find and then choose the ‘Check for Updates’ option.
• As soon as you click on that option, iTunes will start looking for any updates. Now, if some update is available for the iTunes software, then you will get a prompt to download. 
• After that download process gets over, then click on the ‘Install’ button.
• Once the installation process is over, launch the ‘iTunes’ application.
• Next, when the ‘Software Licence Agreement’ page comes up, tap on the ‘Agree’ button.
• At last, follow the instructions that come up on the screen and finish the installation procedure.

Method 6: Disable the Windows Defender Antivirus Temporarily

When the Windows Defender antivirus software blocks the iTunes application, then this issue might show up. If such is the case, you may need to disable the Windows Defender antivirus software. To do that in a proper way, follow the steps given below.

• First, tap on the combination of ‘Windows + I’ keys together. This will launch a new window with the heading ‘Windows Settings’. 
• In this window, there will be various settings categories specific to the Windows OS, that you can change at your will. From this window, locate and then choose the ‘Update & Security’ option.
• Now, a new page within that window will come up, in it, move to the left pane and then choose the ‘Windows Security’ option. 
• Next, navigate to the right pane of that page and then choose the ‘Open Windows Defender Security Center’. Now, a new settings page for the ‘Windows Defender Security Center’ will show up.
• Within this window, locate and then choose the ‘Virus & threat protection settings’ link. When a new page appears, turn off all the options ‘Real-time protection’, ‘Cloud-delivered protection’ and ‘Automatic sample submission’.
• At last, see if the issue gets resolved or not.

Method 7: Update the Windows OS

If the Windows Operating System is obsolete, then this issue can show up. The feasible solution to eradicate this problem is to perform an update to the Windows OS. The steps are as follows.

• First, to choose the ‘Update & Security’ option, navigate to the ‘Method 6’ of this section then follow the first, second and third steps within it.
• Next, a new page will come up, in it, go to the left pane and then choose the ‘Windows Update’ option. Now, move to the right pane with the name ‘Windows Update’.
• Within this page, choose the ‘Check for Updates’ button. This action will automatically look for any updates available for the Windows OS and then download and display them on a list.
• Next, choose the ‘Reboot Now’ button and then those updates will be installed automatically.
• Lastly, when the update to the Windows OS is complete, see if this issue appears again or not.

Follow the fixes given above and fix iTunes error 3600 easily and quickly. However, if the fixes do not work, you can always contact a professional iPhone Repair expert to resolve this issue.