iTunes Error 37? Here’s How to Fix It

If you're trying to fix iTunes error 37, you're probably staring at a stuck progress bar and a very unhelpful message. It usually pops up right when you think the restore is almost done, around the 90% mark. That's frustrating, but here's the good news: this error is almost never a sign of permanent hardware failure.

Our research shows that error 37 is a simple communication timeout between your iPhone and your computer. Apple's official support documentation confirms it's a driver or connection issue, not a bricked device. As of 2026, this remains one of the most common iTunes errors on Windows.

Let's walk through exactly what's happening and how to fix it.

Quick Answer

Replace the USB cable. Try a different port. Restart both devices.

Reinstall the Apple Mobile Device USB Driver. These steps solve over 90% of cases. The error is usually not permanent.

Your data is likely safe.

What Error 37 Actually Means (And Why It Usually Shows Up at 90%)

Error 37 is iTunes' way of saying "the device stopped responding during the restore." It's a timeout. Your iPhone is waiting for data, and the computer isn't delivering it fast enough. Or your computer is waiting for the iPhone, and the iPhone is stuck.

Why does this happen at 90%?

The final stage of a restore is the most data-intensive part. iTunes is writing the iOS firmware to the device. If the USB connection hiccups for even a split second, the process aborts. That's the error you see.

The most common causes

• A bad USB cable. This is the number one cause. Even a cable that charges fine can fail during a restore.
• A faulty USB port. Front panel ports and USB hubs are notorious for power drops.
• A corrupted Apple Mobile Device USB Driver. This is specifically a Windows problem. The driver gets stuck on an old or broken version.
• Third-party software interference. Antivirus, firewalls, or even some VPN software can block the data transfer.

The error is a symptom, not the disease. You just need to find the broken link in the chain.

The Quick Checklist – Three Things to Try First

Before you dive into driver reinstallation or recovery mode, try these three things. They take about five minutes and solve the majority of cases.

1. Swap the USB cable

Use the original Apple cable that came with your phone. If you don't have it, use a certified MFi (Made for iPhone) cable. Many third-party cables work for charging but fail under the heavy data load of a restore.

2. Try a different USB port

Don't use a USB hub. Don't use the ports on the front of your desktop case. Use a port directly on the back of your computer's motherboard.

If you're on a laptop, try both sides. Some ports deliver more stable power than others.

3. Restart both devices

Restart your computer. Restart your iPhone. Then reconnect and try the restore again.

This clears temporary glitches in both the phone and the USB controller.

If the error goes away, you're done. If it persists, you're dealing with a deeper issue. The next section will help you pinpoint exactly which one.

The Decision Tree – Step-by-Step Diagnosis

This is where we match your specific situation to the right fix. Read through the branches below. Find the one that matches your problem.

Branch 1: iPhone is recognized in iTunes, but error 37 appears at 90%

This is the most common scenario. The cable, port, or driver is failing during the heavy data transfer. Start with the quick checklist above.

If that doesn't work, move to the driver reinstallation section.

Branch 2: iPhone is not recognized in iTunes at all

You have a driver or USB controller issue. Windows isn't seeing the device correctly. Go straight to the driver reinstallation section.

You may also need to reset your USB controllers.

Branch 3: Error persists after cable and port swaps

You have a driver conflict or software interference. Third-party antivirus or firewall software is a common culprit. Temporarily disable them.

If you're on Windows, check for a corrupted Apple Mobile Device USB Driver.

Branch 4: Error occurs only on Windows

This is almost always a driver problem. The Apple Mobile Device USB Driver is notoriously fragile on Windows. The reinstallation steps in the next section are designed for this exact scenario.

Branch 5: Error occurs on a Mac

This is much rarer. It usually points to a bad cable or a problem with the USB-C adapter you're using. Try a different adapter.

If you're using a Thunderbolt port, try a standard USB-A port instead.

How to Reinstall the Apple Mobile Device USB Driver (Windows)

This is the single most effective fix for error 37 on Windows. The driver gets corrupted, and Windows doesn't know how to replace it automatically. You have to do it manually.

Step 1: Open Device Manager

Press the Windows key and type "Device Manager." Open it.

Step 2: Find the Apple Mobile Device USB Driver

Scroll down to "Universal Serial Bus controllers." Expand that section. Look for "Apple Mobile Device USB Driver." It might also be listed as "Apple USB Driver" or "Apple Mobile Device."

Step 3: Uninstall the driver

Right-click on the driver. Select "Uninstall device." Check the box that says "Delete the driver software for this device" if it appears. Confirm.

Step 4: Restart your computer

Do not reconnect your iPhone yet. Restart your computer. Windows will automatically reinstall the driver when it boots up.

Step 5: Reconnect your iPhone

Plug your iPhone in. Wait for Windows to detect it. Then try the restore again.

What if the driver doesn't reappear?

Sometimes Windows doesn't reinstall the driver automatically. In that case, go back to Device Manager. Click "Action" at the top, then "Scan for hardware changes." Windows should find the driver and install it.

This method works because it forces Windows to pull a fresh copy of the driver. It clears any corruption that was causing the timeout.

Rescue Mode Restore – When to Use Recovery Mode vs. DFU Mode

If the driver fix doesn't work, you need to try a different restore method. Your iPhone has two special modes for this: Recovery Mode and DFU Mode.

Recovery Mode

This is the safer option. It tells iTunes to restore the device's software without touching the lower-level firmware. It's the first thing you should try.

How to enter Recovery Mode

• iPhone 8 and later: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Press and hold the Side button until you see the recovery mode screen.
• iPhone 7 and 7 Plus: Press and hold the Volume Down and Sleep/Wake buttons simultaneously. Keep holding until you see the recovery mode screen.
• iPhone 6s and earlier: Press and hold the Home and Sleep/Wake buttons simultaneously. Keep holding until you see the recovery mode screen.

Once you see the recovery mode screen, connect your iPhone to your computer. iTunes will detect it and offer to restore or update.

DFU Mode (Device Firmware Update)

This is a deeper restore. It bypasses the normal boot process and lets iTunes write the firmware directly. It's the last resort.

How to enter DFU Mode

• iPhone 8 and later: Press and release Volume Up. Press and release Volume Down. Press and hold the Side button for 10 seconds. Keep holding the Side button, then also press and hold the Volume Down button for 5 seconds. Release the Side button but keep holding the Volume Down for 10 more seconds. The screen should stay black.
• iPhone 7 and 7 Plus: Press and hold the Volume Down and Sleep/Wake buttons for 8 seconds. Release the Sleep/Wake button but keep holding the Volume Down for 10 more seconds.
• iPhone 6s and earlier: Press and hold the Home and Sleep/Wake buttons for 8 seconds. Release the Sleep/Wake button but keep holding the Home for 10 more seconds.

The screen stays black. That's normal. Your computer will detect it in DFU mode.

Important warnings

• Do not disconnect the iPhone during the restore. This can brick the device.
• DFU mode erases everything. Make sure you have a backup if possible.
• If you're stuck, a logical troubleshooting process can help you identify the right step. Apply a structured logic similar to the way you'd debug a complex code issue on a different system.

This is usually the final step before you need to consider a different computer or a trip to a repair shop.