How to Fix USB Device Descriptor Failure Code 43

The Unknown USB Device (Device Descriptor Request Failed) error accompanied by Code 43 occurs when the Windows kernel USB subsystem (usbport.sys or usbhub3.sys) fails to complete an initial GET_DESCRIPTOR control transfer over Endpoint 0 during the bus enumeration sequence. If electrical noise on the differential data lines ($D+$ and $D-$), insufficient VBUS voltage delivery, a corrupted USB hub class driver stack, or persistent register locks in the host controller prevent the peripheral from returning its descriptor payload within the hardware handshake timeout window, Windows terminates port communication and halts the device.

Quick Diagnostic Matrix

1. Discharge Motherboard Flea Power (Cold Hardware Reset)

For Desktop Computers:

1. Shut down Windows completely.

2. Turn the rocker switch on the back of the power supply unit (PSU) to O (Off).

3. Unplug the AC power cord from the wall outlet.

4. Disconnect all external USB peripherals (drives, mice, keyboards, hubs).

5. Press and hold the chassis power button for 30 seconds.
   • Why this works: This drains residual capacitance (“flea power”) across the motherboard circuits, forcing the host controller firmware to reboot cold on the next initialization.

6. Reconnect the power cable, switch the PSU back on, boot Windows, and plug the device directly into a rear motherboard port.

For Laptops:

1. Disconnect the AC charger and detach the battery (if externally removable).

2. Unplug all USB devices and docking stations.

3. Press and hold the physical Power button for 60 seconds.

4. Reconnect the AC adapter and turn the laptop on.

2. Disable USB Selective Suspend and Fast Startup

Step A: Disable USB Selective Suspend

1. Press Windows Key + R, type powercfg.cpl, and press Enter.

2. Click Change plan settings next to your active power configuration.

3. Click Change advanced power settings.

4. In the dialogue tree, expand USB settings > USB selective suspend setting.

5. Change both On battery and Plugged in to Disabled.

6. Click Apply, then click OK.

[Power Options (powercfg.cpl)]
 └── Change plan settings
      └── Change advanced power settings
           └── USB settings
                └── USB selective suspend setting > [Set to DISABLED]

Step B: Disable Windows Fast Startup

1. In the left-hand menu of powercfg.cpl, select Choose what the power buttons do.

2. Click the shield link labeled Change settings that are currently unavailable.

3. Under Shutdown settings, uncheck the box next to Turn on fast startup (recommended).

4. Click Save changes and restart the machine.

3. Reinstall Host Controllers and Root Hub Stacks

1. Press Windows Key + X and select Device Manager (or run devmgmt.msc).

2. Scroll to the bottom and expand Universal Serial Bus controllers.

3. Right-click Unknown USB Device (Device Descriptor Request Failed) and select Uninstall device. Confirm by clicking Uninstall.

4. Right-click your primary USB Root Hub (USB 3.0) (or Generic USB Hub) and select Uninstall device.
   • (Note: Your mouse or keyboard may stop responding temporarily if connected to that hub).

5. Using your keyboard or physical power button, restart your PC:
   • Press Windows Key + X, press U, then press R.

6. Upon reboot, Windows will re-read the ACPI tables and automatically reinstall usbhub3.inf and usbxchi.inf.

[Device Manager (devmgmt.msc)]
 └── Universal Serial Bus controllers
      ├── Unknown USB Device (Descriptor Failed) > Uninstall
      └── USB Root Hub (USB 3.0) > Uninstall
           └── Restart Computer (Forces hardware re-enumeration)

4. Delete Corrupted Class Upper and Lower Registry Filters

1. Press Windows Key + R, type regedit, and press Enter.

2. Navigate to the USB device class registry path:
   Plaintext

   HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlClass{36fc9e60-c465-11cf-8056-444553540000}
   

3. With the {36fc9e60...} key highlighted in the left pane, inspect the right-side values:
   • Look for strings named UpperFilters and LowerFilters.

4. If either entry is present, right-click it and choose Delete. Confirm removal.
   • Caution: Do not delete or edit any other values inside this key.

5. Close the Registry Editor and reboot Windows to reload the unmodified USB driver stack.

5. Isolate Differential Data Lines and Power Sag

[USB Type-A Pin Interface]
 ┌───────────────────────┐
 │ [Pin 1: VBUS (5V)]    │ <─── Voltage sag (<4.75V) causes controller brownout
 │ [Pin 2: Data- (D-)]   │ <─── Severed/bent pin halts GET_DESCRIPTOR handshake
 │ [Pin 3: Data+ (D+)]   │ <─── High resistance/oxidation drops bit sync
 │ [Pin 4: Ground (GND)] │
 └───────────────────────┘

• Bypass Front-Panel Ports: Front-panel chassis ports rely on long, unshielded internal wiring harnesses that run adjacent to high-noise components (power supplies and GPU inductors). Connect the device directly to the rear motherboard I/O panel.

• Eliminate Unpowered Hubs: Passive (bus-powered) USB splitters divide a single 500mA–900mA port supply across multiple devices. If total power consumption drops port voltage below $4.75text{V}$, the peripheral cannot drive the differential lines, triggering a descriptor failure. Switch to a dedicated wall-powered USB hub.

• Inspect Physical Contacts: Use a direct light source to inspect the plug and port pins:
  • Check whether Pin 2 or Pin 3 is bent backward, broken, or covered in debris. If the power pins make contact but the data pins do not, the device’s status LED will illuminate, but Windows will fail descriptor retrieval immediately.

  • Clean dirty or oxidized pins using an interdental brush lightly moistened with 99% isopropyl alcohol (IPA).

6. Purge Stale USB Descriptors via USBDeview

1. Download the standalone diagnostic utility USBDeview (from NirSoft).

2. Right-click USBDeview.exe and select Run as administrator.

3. In the top toolbar, go to Options and verify that Show Disconnected Devices is checked.

4. Locate entries highlighted in pink, marked as Unknown USB Device, Failed, or showing blank Vendor IDs (0000) and Product IDs (0000).

5. Select all corrupted or conflicting entries, right-click, and select Uninstall Selected Devices.

6. Unplug the device, restart your PC, and reconnect the peripheral to force the USB subsystem to run a complete, un-cached bus enumeration cycle from scratch.