Fixed: Unknown USB Device Descriptor Request Failed

Unknown USB Device Error 43

About the Error: A Request for the USB Device Descriptor Failed

This error occurs when Windows is unable to read the USB device descriptor, which contains important information about the device such as its type, manufacturer, and capabilities. When this happens,device does not show up in File Explorer, cannot be accessed, and any attempt to use it results in a "Unknown USB Device (Device Descriptor Request Failed)"message.

Sometimes, Device Manager will mark the device with a yellow exclamation mark and the Drive Staus in Device Properties will display Code 43 (as the last screenshot shown), indicating that the hardware is not functioning correctly. So, what cause this issue? There can be several reasons, with the most common including:

• Insufficient Power Supply: Some USB devices, especially external drives, require more power than a single USB port can provide.
• Loose or Faulty USB Connection: A damaged USB cable, worn-out connector, or faulty USB port can prevent proper electrical contact, disrupting communication with the device.
• Driver Issues: Outdated, corrupted, or incompatible drivers may prevent Windows from communicating correctly with the USB device.
• Hardware Faults: The USB device itself may be damaged, such as having bad sectors, or the USB controller on the computer may be unstable or corrupted.
• System or Software Errors: Missing or corrupted system files related to USB functionality, registry glitches, or software conflicts can interfere with device recognition.
• BIOS/UEFI or System Settings: Incorrect or outdated BIOS/UEFI settings can affect USB detection. Overclocking or system instability may also disrupt USB communication.
• USB-C Compatibility Problems: Some USB-C devices may not function correctly on certain ports.
• Outdated Windows Version: Missing Windows updates or outdated system files can cause compatibility issues that affect USB device communication.
• Temporary System Glitches: Occasionally, Windows system settings or registry entries can prevent proper recognition of the USB device.

How to Fix "Unknown USB Device Descriptor Request Failed" Issue?

When your USB device cannot be recognized, try these solutions. We will start with the simplest checks and move toward more advanced fixes if the problem persists.

Method 1. Check Power and Connection

Sometimes the USB device isn’t receiving enough power, especially for external drives, or the connection is loose.

Step 1. Disconnect the USB device from your computer and inspect the cable and connectors for damage.

Step 2. Plug the device into a different USB port or use a powered USB hub to ensure adequate power.

Step 3. Check if the device is now recognized in File Explorer or Device Manager.

Method 2. Use a USB-C Adapter

Some USB-C devices may not function correctly with certain ports. If your device is USB-C, use a USB-C to USB-A adapter and connect to a USB 3.0 port. This often resolves compatibility issues and allows Windows to read the device descriptor correctly.

Method 3. Power Cycle Your System

If the device still fails, perform a full power cycle. Shut down your PC completely, unplug the power adapter (for laptops, also remove the battery if possible), wait 1–2 minutes, reconnect power, and boot up. Plug the USB device back in and check if it is recognized.

Method 4. Update or Reinstall USB Drivers

Outdated or corrupted drivers can prevent proper communication with the device. Open Device Manager (press Win + X > Device Manager), expand "Universal Serial Bus controllers,"and look for the device with a yellow exclamation mark.

Right-click it and choose "Update driver", then select "Search automatically for drivers". If updating fails, choose "Uninstall device", disconnect the USB device, restart your PC, and reconnect it so Windows reinstalls the driver automatically.

Method 5. Disable USB Selective Suspend and Power Saving

Windows sometimes turns off USB ports to save power, which can cause descriptor failures.

Step 1. Press "Win + S"and type "Control Panel", then click "Open".

Step 2. In the Control Panel, click on "Hardware and Sound", then go to "Power Options", select "Change power-saving settings".

Step 3. Click the "Change plan settings" link next to the power plan you are currently using, and click "Change advanced power settings".

Step 3. In the new window, expand "USB settings", then double click "USB selective suspend setting", and set it to"Disabled".

Step 4. Click "Apply", restart your computer, and reconnect the USB device.

Method 6. Disable Fast Startup

Fast Startup in Windows can sometimes interfere with USB device initialization, causing descriptor request failures. In this situation, we can try disabling it.

Step 1. Click the "Power Options" (like you do in the last method). On the left sidebar, click "Choose what the power buttons do".

Step 2. Click "Change settings that are currently unavailable" at the top of the page.

Step 3. Under "Shutdown settings", uncheck "Turn on fast startup (recommended)".Click "Save changes", restart your computer, and reconnect the USB device to see if it is now recognized.

Method 7. Run Windows Hardware Troubleshooter

When Windows fails to recognize a USB device, there may be underlying hardware or system configuration issues. Running the built-in Windows Hardware Troubleshooter can automatically detect and fix problems that prevent your USB device from being recognized.

Step 1. Press "Win + R" to open the Run dialog, type "msdt.exe -id DeviceDiagnostic", and press Enter. This will launch the Hardware and Devices Troubleshooter.

Step 2. Click "Next" and allow Windows to scan for any issues with connected hardware, including USB devices.

Step 3. Follow the on-screen instructions to apply any recommended fixes. Once the process is complete, restart your computer.

After your computer restarts, reconnect the USB device and check if it is recognized correctly. Running the troubleshooter often resolves minor hardware or driver conflicts that can trigger the "Unknown USB Device (Device Descriptor Request Failed)" error.

Method 8. Check and Repair Disk Error

If the USB device is recognized but still not functioning properly, there may be file system errors or bad sectors on the drive. Windows provides a built-in(CHKDSK)tool to scan and repair these errors, which can often restore proper device functionality.

Step 1. Press "Win + S", type "cmd", right-click "Command Prompt", and select "Run as administrator".

Step 2. In the Command Prompt, type chkdsk g: /f /r and press Enter. Replace g: with your USB drive letter. The /f flag fixes errors,and /r locates bad sectors and recovers readable information.

Step 3. Wait for the process to complete. Depending on the size and condition of the USB drive, this may take some time.

Once CHKDSK finishes, safely eject the USB drive, reconnect it, and check if the "Unknown USB Device (Device Descriptor Request Failed)" error has been resolved.

Method 9. Fix Registry Issues Affecting USB Recognition

Sometimes, Windows registry entries related to USB devices can become corrupted or misconfigured, preventing proper recognition of your USB drive. Correcting or resetting these entries can often resolve the "Unknown USB DeviceDescriptor Request Failedcode 43" error.

Step 1. Press "Win + R" to open the Run dialog, type "regedit", and press Enter to launch the Registry Editor.

Step 2. Navigate to the path

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{36FC9E60-C465-11CF-8056-444553540000}. This registry key stores USB device information.

Step 3. In the right pane, look for entries named UpperFilters and LowerFilters. Right-click each one and select "Delete". Confirm the deletion if prompted.

Step 4. Close the Registry Editor and restart your computer. After restarting, reconnect your USB device and check if it is recognized correctly.

Resetting these registry entries clears corrupted or conflicting USB settings, allowing Windows to properly detect and communicate with the USB device.

Method 10. Check and Update BIOS/UEFI Settings

When USB devices are not recognized due to BIOS/UEFI or system settings, adjusting or updating the firmware can resolve the issue. Incorrect configurations or outdated firmware may interfere with USB initialization.

Step 1. Restart your computer and enter the BIOS/UEFI setup by pressing the designated key during boot (commonly F2, Del, or Esc, depending on your motherboard).

Step 2. Once in BIOS/UEFI, navigate to the settings related to USB configuration. Ensure that all USB ports are enabled and set to their default modes. If there is an option for "Legacy USB Support" or "XHCI Hand-off," make sure it is enabled.

Step 3. Save changes in BIOS/UEFI and restart your computer. Reconnect the USB device and check if it is now recognized.

If your BIOS/UEFI version is outdated, visit your motherboard or laptop manufacturer’s website to download the latest firmware update. Follow the official instructions carefully to flash the BIOS/UEFI.

(Optional) Recover Data from the USB Device

If you lost files on the USB drive after fixing the "Unknown USB Device (Device Descriptor Request Failed)" error, you might need professional data recovery software. Among all available options, we highly recommend MyRecover.

Step 1. Download and install MyRecover on your computer.Launch it and select the USB drive you want to recover. Click "Scan".

Step 2. It willperform a full scan and detect all recoverable files. Once the scan is complete, preview the files in the results. Use the search bar or filters to locate specific files you need, such as images, videos, documents, or music.

Step 3. Select the files you want to restore, click "Recover," and choose a safe location on your computer to save them. Do not save recovered files back to the same USB drive to prevent overwriting other lost data.

Bottom Line

While the "Unknown USB Device (Device Descriptor Request Failed)" error can be alarming, you can try the above solutions. For situations where data loss occurs during the troubleshooting process, using professional recovery software like MyRecover ensures that your important fileslike photos, documents, videos, and morecan be safely restored. Moreover, even if your computer cannot boot up as normal, you can use it to create a bootable rescue media and recover data from crashed PC.