The error "A device attached to the system is not functioning" is a common issue encountered on Windows-based PCs, iPhones, and Android devices when there is a communication breakdown between the system and external devices. Today, you can follow step-by-step instructions to resolve the problem on Windows computers, as well as on mobile devices like iPhone and Android.
The "A device attached to the system is not functioning" error typically occurs when there is a communication breakdown between the device (such as an external drive, Android phone, or iPhone) and the Windows system, preventing them from establishing a proper connection.
Here are some of the most common reasons why this error occurs:
⭕Faulty or Loose USB Connections
⭕Outdated or Corrupted Device Drivers
⭕USB Power Issues
⭕Device Malfunction or Hardware Failure
⭕Windows OS Issues (Driver Conflicts or Corrupt Files)
⭕Windows 10/11 USB Controller Issues
⭕Incompatibility Between Device and OS
⭕Corrupted File System on External Drives
⭕Antivirus or Security Software Interference
⭕USB Port Damage (Windows or Mobile)
The cause of the "A device attached to the system is not functioning" error can lie either within the Windows system or on the connected device (regular external drives, Android or iPhone). Below are detailed troubleshooting steps to help you resolve the issue, depending on where the problem originates.
To troubleshoot the "A device attached to the system is not functioning" error on Windows 11 or Windows 10, follow these methods:
A simple restart can often resolve temporary glitches that might be causing the device connection issue. Click on the Start menu > Power > Restart.
2. Check Physical Connections
Sometimes, the connection between the device and the system can be disrupted by a loose or faulty USB port or cable. If the device is not securely connected, the system may not be able to detect it properly.
Device drivers allow your system to communicate with hardware components. If the drivers are outdated, missing, or corrupted, it can result in the system being unable to properly interface with the device.
Update the device drivers, especially for USB hubs, storage devices, printers, or external peripherals. You can do this through theDevice Manager on Windows: press "win+X" at the same time, choose "Device Manager", expand the "Disk drives", select the problematic device and choose "Update Driver". Then follow the instructions to complete the process.
If updating the driver doesn't resolve the issue, you can try uninstalling the device and reinstalling it: Right-click on the device in Device Manager and select "Uninstall device". Restart your computer, and Windows will automatically detect the device and reinstall the appropriate drivers.
4. Check USB Power
Some external devices (like hard drives or printers) require more power than others. If your USB ports are not supplying enough power (due to power management settings or limitations), the device might not work properly. For Windows, try disabling USB selective suspend settings in the Power Options menu. You can also use a powered USB hub or try connecting the device directly to another port to see if power is the issue.
Step 1. Press "Windows + X", then select "Power Options".
Step 2. In the "Power & Sleep" settings, click on "Additional power settings" on the right side of the screen. This will open the Power Options window.
Step 3. Next to your selected power plan (usually Balanced or High Performance), click "Change plan settings".
Step 4. In the next window, click on "Change advanced power settings".
Step 5. In the Power Options dialog, expand the USB settings category. Then expand the USB selective suspend setting. Set Setting to "Disabled".
Click "Apply", then "OK"to save your changes.
If the device requires more power than what the USB port can provide (common for external hard drives, printers, etc.), using a powered USB hub can help. A powered hub has its own power supply, which ensures that the connected devices get sufficient power.
5. Run the Hardware Troubleshooter
Windows has a built-in tool that can automatically detect and fix problems with your devices. You can run the Hardware and Devices troubleshooter to check for any issues with your connected devices.
Step 1: Press "Windows + I" to open the Settings menu. Go to "Update & Security".
Step 2: In the left pane, select "Troubleshoot". Under "Find and fix other problems", select "Hardware and Devices".
Step 3: Click "Run the troubleshooter" and follow the on-screen instructions.
This tool will attempt to automatically find and fix any issues related to your hardware, including any connection problems with your external devices.
Sometimes, the error could be due to outdated system files. Microsoft regularly releases updates to address hardware compatibility issues.
Step 1: Press "Windows + I" to open the Settings.
Step 2: Go to "Update & Security" and click on "Windows Update".
Step 3: Click "Check for updates".
If updates are available, install them and restart your computer to apply the changes.
Windows maintains logs of all system activities, including hardware errors. You can check the Event Viewer for detailed information on the device error.
Step 1: Press "Windows + X" and select "Event Viewer".
Step 2: In the Event Viewer window, expand "Windows Logs" and select "System".
Step 3: Look for Error or Warning entries related to the device (you can filter the logs if necessary).
Step 4: Double-click on the error to view more details. This may give you specific information about what is causing the issue.
Corrupted system files can lead to unexpected errors including "A device attached to the system is not functioning". If so, running the System File Checker (SFC) tool can help resolve issues.
Step 1. Press "Windows + X" and select Command Prompt (Admin) or Windows PowerShell (Admin).
Step 2. Type "sfc /scannow" and press Enter.
Step 3. Wait for the scan to complete and follow any instructions to fix issues.
9. Apply CHKDSK Tool
Running the CHKDSK (Check Disk) tool can help identify and fix problems with your hard drive, such as bad sectors or file system errors, which might be contributing to the "A device attached to the system is not functioning" error.
Just run the following command in the Command Prompt window.
chkdsk g: /f /r
g:: Specifies the drive letter you want to check. (If you're checking a different drive, change the letter accordingly, e.g., D: or E:)
If all above methods doesn't resolve the issue, or if the drive continues to malfunction, formatting the drive may be your last resort. Formatting erases all data on the drive, so make sure to recover files from the inaccessible drive before proceeding.
If you cannot see the drive in File Explorer or Disk Management, directly force format it via DiskPart. Open Command Prompt as admin, and then input the below commands in turn.
If you meet the error when connecting your Android phone to Windows computer, you can try adjusting some related setting on your mobiles.
Android devices can switch between different connection modes (charging, file transfer, etc.), and if it’s set to the wrong mode, the system may not recognize the device.
Step 1. Connect your Android device to the computer.
Step 2. Pull down the notification shade on your Android phone.
Step 3. Tap the USB charging this device notification and select "File Transfer (MTP)" or "Media Transfer Protocol".
USB Debugging allows deeper communication between your Android device and the computer.
Step 1. Go to "Settings > System&Updates".
Step 2. Then tap "Developer options".
Step 4. Enable "USB debugging".
Then reconnect your device to the computer.
Sometimes, the issue could be caused by a software bug or compatibility problem that has already been addressed in a system update. Keeping your Android device up to date ensures that any known issues are fixed and may resolve the device connection problem.
Step 1. Go to "Settings > System&Updates".
Step 2. Tap on "Software Updates".
Step 3. Wait for the system to check for any available updates. If updates are found, download and install them.
When dealing with the "A device attached to the system is not functioning" error on an iPhone, the troubleshooting steps can be slightly different from the Android.
Just like with other devices, a loose or faulty cable or port can cause connection issues. Start by ensuring that everything is securely connected.
Step 1: Inspect the USB or Lightning cable for any visible damage.
Step 2: Plug the cable into a different port on your computer or charger.
Step 3: Try using a different cable, especially if the cable is old or frayed.
Step 4: Clean both the Lightning port on your iPhone and the USB port on your computer to ensure there is no debris blocking the connection.
If you're connecting your iPhone for the first time, you must explicitly allow it to communicate with your computer.
Plug your iPhone into the computer. If prompted on your iPhone, tap "Trust" and enter your device passcode. This ensures that the computer has permission to access the device.
3. Update iTunes or Finder
The error can occur if iTunes (on Windows) or Finder (on macOS) is outdated and doesn't support the latest iPhone versions. Ensure that you have the latest version of iTunes on Windows or macOS. You can update iTunes from the Microsoft Store or the Apple website.
Finally, keeping your iPhone’s software up-to-date can fix bugs related to device connectivity. Go to "Settings > General > Software Update" and install any available updates.
These steps should help you fix the "A device attached to the system is not functioning" error in Windows, Android or iPhone. We hope these steps will help you successfully fix the issue. If, unfortunately, you’ve lost files on your device, try using MyRecover to perform data recovery without using a backup.