Try another port (directly on the PC, not a hub) and another cable, shut the PC down and unplug it for a minute, then in Device Manager uninstall Unknown USB Device and the USB Root Hubs and restart. Turn off USB selective suspend in power settings.

The short explanation

When a USB device connects, Windows asks it for a descriptor that says what it is. If the reply is missing or corrupted (bad cable, not enough power, a confused port, faulty device), the device shows as unknown. (A charge-only cable is different: the device isn't detected at all, with no sound or message.)

How it shows up

  • Pop-up: “USB device not recognized”.
  • Device Manager shows “Unknown USB Device (Device Descriptor Request Failed)”.
  • The device works on another computer.

Common causes

  • Faulty or charge-only cable, or a bad port/hub.
  • Not enough power (unpowered hubs, bus-powered drives).
  • USB selective suspend.
  • Corrupted USB controller drivers or a faulty device.

How to fix it, step by step

  1. Change port and cablePlug directly into the PC (rear ports on desktops) with a known-good data cable.
  2. Power-drain the PCShut down, unplug power (and remove a removable laptop battery) for 60 seconds, then start and reconnect.
  3. Reinstall USB driversDevice Manager → Universal Serial Bus controllers: uninstall Unknown USB Device and each USB Root Hub, then restart; Windows reinstalls them.
  4. Disable selective suspendControl Panel → Power Options → Change plan settings → Advanced → USB settings → USB selective suspend → Disabled.
  5. Update chipset driversInstall the chipset/USB drivers from the PC or motherboard maker.
  6. Test the device elsewhereIf it fails on every computer, the device or cable is faulty.
How to confirm the fix: The device appears with its proper name in Device Manager and works.

Keeping it from coming back

Use powered hubs for drives and keep chipset drivers current.