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USB device not recognized: finding the real cause

DeviceInBox editorial team · Last updated October 6, 2026

"USB device not recognized" is the balloon Windows shows when a device was plugged in, drew power and started to answer, but the conversation broke down before Windows learned what it was. In Device Manager the result is "Unknown USB Device" under Universal Serial Bus controllers, often with Code 43. The cause is as likely to be the cable, the port or the power budget as the driver.

Unknown USB Device entry under Universal Serial Bus controllers in Device Manager
The device reached Windows but never identified itself.
Windows notification saying a USB device was not recognized
The notification and the Device Manager entry describe the same event.

The five checks that fix most cases

  1. Try another port, and prefer a port on the back of a desktop. Front panel ports run on an internal cable that is often the weakest link.
  2. Try another cable. Charge-only cables have no data wires at all, which produces exactly this message.
  3. Remove hubs and docks from the chain and connect the device straight to the PC.
  4. Shut down fully (hold Shift while clicking Shut down so Windows does not hibernate), unplug the power for half a minute, start again. This resets the USB controllers properly, which a normal restart does not.
  5. Try the device on another computer. If it fails there too, the device or its cable is the problem.
Chain from device through cable, hub and port to the USB controller, with the weak points marked
Every link in the chain can produce the same message.

Power is a common and quiet cause

An external drive, a USB-powered printer or a bus-powered dock can need more current than a shared port provides. A passive hub splits one port's budget between everything on it. Symptoms are a device that works alone but not next to others, or one that works on a desktop and fails on a laptop running on battery.

  • Use a powered hub for drives and docks.
  • On a laptop, plug the charger in before testing.
  • Open Device Manager, each USB Root Hub, Power Management tab, and clear "Allow the computer to turn off this device to save power" for the hub the device sits on.
Power Management tab of a USB Root Hub with the power saving option cleared
Selective suspend puts hubs to sleep and some devices never wake up.

Reset the USB stack in Windows

If the hardware checks out, remove the controllers and let Windows rebuild them.

  1. In Device Manager, expand Universal Serial Bus controllers.
  2. Right-click each Unknown USB Device entry and choose Uninstall device.
  3. Then uninstall every USB Root Hub, one after another. The mouse and keyboard may stop responding for a moment.
  4. Restart. Windows reinstalls the controllers and hubs from scratch.

Also check Settings, System, Power and battery, Power mode, and open the advanced settings: USB selective suspend can be disabled there for a test.

When it really is the driver

Once the device identifies itself, the message changes. If Device Manager shows a proper hardware ID such as USB\VID_0BDA&PID_8179 rather than VID_0000&PID_0002, you are past the hardware stage and only need the driver for that ID (how to read it).

An ID of USB\VID_0000&PID_0002 means the opposite: nothing was read from the device, so no driver can help. That case is covered in Device Descriptor Request Failed.

Check the controller itself

If every USB port on the machine behaves this way, look at the controller rather than the devices. Intel and AMD chipset packages install the controller INF files, and on desktops with an add-in card the ASMedia or VIA driver matters.

Hardware IDDeviceDrivers
PCI\VEN_1B21&DEV_1242ASM1142 USB 3.1 Host Controller7
PCI\VEN_1106&DEV_3483VL805 USB 3.0 Host Controller5
PCI\VEN_1912&DEV_0015uPD720202 USB 3.0 Host Controller1

Related: Code 43, Device Descriptor Request Failed and Unknown device.

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