USB Device Not Recognized

USB device not recognized is the message Windows shows when something is plugged in but the computer cannot read what it is. The full text usually says: "The last USB device you connected to this computer malfunctioned, and Windows does not recognize it." The cause is most often the cable, the port, a hub without enough power, or USB power saving switching the port off. Unplug the device, plug it straight into a different port on the computer with a different cable, and restart. To confirm a storage device works properly afterwards, run the usb speed test. It reads and writes real data, so a drive that drops out or slows to a crawl shows up straight away.

Quick checks

• Another port. Use a port on the computer itself. On a desktop, the ports on the back come straight off the motherboard, while front ports run through an internal cable that can work loose.
• Another cable. Many USB cables, especially those bundled with chargers and controllers, carry power only and no data. A device that charges but is never recognized usually has one of these.
• Restart the computer, then plug the device in once Windows has finished starting.
• Unplug everything else on USB. Then reconnect devices one at a time. A failing device elsewhere can trigger the message for a different port.
• Try the device on another computer. If it fails there too, the device or its cable is faulty, not your computer.

Find the device Windows means

The message names no device, so find it first.

1. Right-click Start and open Device Manager.
2. Expand Universal Serial Bus controllers and look for Unknown USB Device (Device Descriptor Request Failed) or another entry with a yellow warning sign.
3. Double-click it. The Device status box often shows Code 43, which means the device reported a problem and Windows stopped it.
4. Unplug USB devices one at a time and watch the list. The warning disappears when you remove the device at fault.

If the message keeps popping up with nothing plugged in, a built-in USB device is failing, such as a webcam, fingerprint reader, Bluetooth adapter or card reader. They show up in Device Manager under their own sections.

Turn off USB power saving

Windows can cut power to USB ports it thinks are idle. Some devices do not wake up cleanly, and Windows then reports them as malfunctioned.

USB selective suspend:

1. Open Control Panel, Power Options and select Change plan settings next to your plan.
2. Select Change advanced power settings.
3. Expand USB settings, then USB selective suspend setting, and set it to Disabled. On a laptop, set both On battery and Plugged in.
4. Select Apply, then OK.

If USB settings is missing from the list, right-click Start and open Terminal (Admin), or Windows PowerShell (Admin) on Windows 10. Run these commands one after the other, then restart:

• powercfg /setacvalueindex SCHEME_CURRENT 2a737441-1930-4402-8d77-b2bebba308a3 48e6b7a6-50f5-4782-a5d4-53bb8f07e226 0
• On a laptop, also run powercfg /setdcvalueindex SCHEME_CURRENT 2a737441-1930-4402-8d77-b2bebba308a3 48e6b7a6-50f5-4782-a5d4-53bb8f07e226 0 for battery power.
• powercfg /setactive SCHEME_CURRENT

Power management on the USB hubs: in Device Manager, expand Universal Serial Bus controllers, double-click each USB Root Hub, open the Power Management tab and untick Allow the computer to turn off this device to save power.

Windows 11 laptops: open Settings, Bluetooth & devices, USB and turn off USB battery saver if a device stops working after the screen turns off.

Reinstall the USB drivers

1. In Device Manager, right-click the entry with the warning and select Uninstall device. Unplug the device, wait a minute and plug it back in.
2. If that fails, expand Universal Serial Bus controllers and uninstall each entry in turn, then restart. Windows reinstalls the controllers by itself when it starts. Use a wired keyboard and mouse on a desktop while you do this, or a laptop's built-in ones.
3. Install the chipset and USB drivers for your exact model from your computer maker's support site. In Windows 11, also check Settings, Windows Update, Advanced options, Optional updates for driver updates.

Hubs, docks and power

A USB 2.0 port supplies 500 mA, a USB 3 port 900 mA, and a USB-C port up to 3 A at 5 V. A bus powered hub shares that between everything plugged into it, so a portable hard drive, a webcam and a phone together can starve each other. Microsoft's own advice for an external drive that is not recognized is to plug it straight into the computer, because a hub without its own power supply may not give it enough.

• Connect the hub's or dock's power adapter if it has one.
• Move power hungry devices, such as portable drives and audio interfaces, to ports on the computer.
• Update the dock's firmware from its maker.

Check the BIOS

On some business laptops and desktops, USB ports can be switched off in the BIOS or UEFI settings, under names such as USB Configuration on Dell, Port Options on HP or I/O Port Access on Lenovo ThinkPads. If one or more ports have never worked on a work computer, check there or ask your IT team. Updating the BIOS from the maker's support site also fixes USB problems on some models.

USB drives and memory cards

When a USB drive connects without an error but does not show in File Explorer:

1. Right-click Start and open Disk Management.
2. If the drive appears with no letter, right-click it, choose Change Drive Letter and Paths and add one.
3. If it shows as Unallocated or its file system as RAW, Windows cannot read it. Recover any files first, then format it.

A cheap high capacity drive that disconnects, corrupts files or fills up early may be a fake. The fake flash drive test writes to the whole drive and finds its real size.

Keyboards, mice, controllers and phones

• Keyboards and mice: once recognized, check every key and button with the keyboard test and the mouse test.
• Game controllers: use a data cable, not a charge-only one, and update the controller's firmware with its maker's app, such as the Xbox Accessories app. The controller not connecting to pc guide covers Bluetooth and Steam settings.
• Android phones: the phone charges but stays invisible until you pull down the notification about USB and choose File transfer.
• iPhones: unlock your iPhone and tap Trust when it asks whether to trust the computer. If it charges slowly or not at all as well, see phone not charging when plugged in.

USB device not recognized on a Mac

1. Hold Option, open the Apple menu and choose System Information, then select USB. If the device is listed there, the Mac sees it and the problem is its software or format.
2. On an Apple silicon MacBook, look for a prompt asking to allow the accessory, and allow it. The setting is Allow accessories to connect in System Settings, Privacy & Security, under Accessories on recent macOS versions. A device you refused stays unrecognized until you connect it again and allow it.
3. Connect it directly, not through a hub, and try another cable.
4. For drives, open Disk Utility, choose View, then Show All Devices, and mount the drive. A Windows formatted NTFS drive can be read but not written by macOS. Format with exFAT to use a drive on both systems.

When it is a hardware fault

Suspect the device when it fails on every port of two different computers with two cables. Suspect the port when a known good device fails in one port only, or when the port feels loose, the connector inside is bent or there is a burnt smell. A USB-C port that charges but carries no data, or the reverse, also has a worn connector.

For the device, check the maker's warranty, which is often one to three years on drives, keyboards and controllers. A port on a laptop or desktop motherboard is a repair job. Until then, a powered USB hub on a working port is a practical workaround.

USB not recognized questions