How to Fix a USB Device Not Recognized

You plug in your USB drive and Windows pops up with a dreaded yellow warning: “USB Device Not Recognized.” The drive doesn’t appear in File Explorer, nothing responds, and you have no idea what went wrong. Don’t panic — this is one of the most common Windows errors, and in the vast majority of cases it’s fixable in under ten minutes without any technical background.

This guide covers every cause and every fix, step by step, for Windows 10, Windows 11, and macOS. Each fix is clearly labelled so you can skip straight to what applies to you.

Still not working after those? Keep reading — we’ll cover everything, including driver corruption, power management issues, and what to do when the device itself is faulty.

Why does “USB Device Not Recognized” happen?

When you plug in a USB device, your operating system runs through a short sequence: it detects the connection, loads the appropriate driver, and assigns the device a drive letter so it appears in File Explorer. The “not recognized” error means something broke at one of those stages. The four most common culprits are:

• Driver failure — the USB driver is corrupted, outdated, or conflicting with a recent Windows update
• Physical damage — a bent pin in the port, a damaged cable, or a failing flash chip inside the drive
• Power delivery issue — the port or USB hub isn’t supplying enough power for the device to initialise
• File system problem — the drive’s partition is unformatted, RAW, or missing a drive letter

Quick self-diagnosis: Before anything else, plug the USB into a different computer. If the same error appears on another machine, the device itself is likely faulty. If it works fine elsewhere, the problem is with your computer’s software or ports — and this guide will fix it.

Step 1 — Basic checks before anything else

These take less than two minutes and solve the problem for most people. Work through them in order.

Try a different USB port

USB 3.0 ports (usually blue) and USB 2.0 ports have separate controllers. If one controller has a glitch, the other may work fine. On a desktop, try the ports on the rear panel — they connect directly to the motherboard rather than through a front-panel cable, making them more reliable.

Try a different cable or device

Swap the USB cable if your device uses a detachable one. Try a different flash drive or external drive to confirm whether the problem follows the device or stays with your computer.

Restart your computer

A full restart clears the USB controller’s state in memory. A fast-startup shutdown on Windows 11/10 does not do the same thing — make sure you choose Restart, not Shut Down.

Check Device Manager for error codes

1. Press Win + X and click Device Manager
2. Expand Universal Serial Bus controllers
3. Look for any entry with a yellow exclamation mark (!)
4. Right-click that entry and choose Properties to see the error code

Check USB power management

Windows can cut power to USB ports to save energy, which sometimes prevents recognition:

1. In Device Manager, expand Universal Serial Bus controllers
2. Right-click USB Root Hub → Properties
3. Go to the Power Management tab
4. Uncheck “Allow the computer to turn off this device to save power”
5. Click OK and repeat for all USB Root Hub entries

Fix 1 — Update or reinstall USB drivers

Driver issues are the single most common cause of this error, especially after a Windows Update. Follow these steps in order.

Update the driver automatically (Windows)

1. Open Device Manager (Win + X → Device Manager)
2. Expand Universal Serial Bus controllers
3. Right-click the device showing an error → Update driver
4. Choose “Search automatically for drivers”
5. Restart your computer when prompted

Uninstall and reinstall the driver

If updating didn’t help, a clean reinstall often does:

1. In Device Manager, right-click the USB device → Uninstall device
2. Check “Delete the driver software for this device” if the option appears
3. Click Uninstall
4. Restart your PC — Windows will automatically reinstall the correct driver on boot

Roll back the driver (if the error started after a Windows Update)

1. In Device Manager, right-click the USB controller → Properties
2. Click the Driver tab
3. Click Roll Back Driver (greyed out if no previous driver is saved)
4. Select a reason when prompted and confirm

macOS — no driver install needed

macOS manages USB drivers automatically. If your device isn’t detected, open Apple Menu → System Information → USB and check whether the hardware appears in the USB device tree. If it does not appear at all, the device or cable is the likely fault. If it does appear, proceed to the Disk Utility fix in section 6 below.

Fix 2 — Run the Windows troubleshooter and system repair tools

Windows includes built-in diagnostics that most users never find. These can automatically detect and repair USB issues caused by corrupted system files.

Hardware and Devices troubleshooter

Windows 10: Settings → Update & Security → Troubleshoot → Additional troubleshooters → Hardware and Devices → Run the troubleshooter

Windows 11: The Hardware and Devices troubleshooter was removed from the Settings UI but still runs via Command Prompt. Paste this into the Run dialog (Win + R) and press Enter:

System File Checker (SFC)

Corrupted Windows system files can block USB drivers from loading correctly. Open Command Prompt as Administrator (search “cmd” → right-click → Run as administrator) and run:

Wait for the scan to complete (5–10 minutes). If it reports “Windows Resource Protection found corrupt files and repaired them,” restart and test your USB again.

DISM repair

If SFC couldn’t fix everything, DISM repairs the underlying Windows image:

This requires an internet connection and takes 10–20 minutes. Restart when it finishes, then run sfc /scannow one more time.

Fix 3 — Assign a drive letter (USB detected but not visible in File Explorer)

If your USB device shows up in Device Manager without errors but doesn’t appear in File Explorer, the problem is almost always a missing drive letter. This is common with drives formatted on Linux or macOS, or drives previously used on another system.

Windows — Disk Management

1. Press Win + X → Disk Management
2. Look for a disk labelled Removable or showing without a drive letter
3. Right-click the volume → Change Drive Letter and Paths
4. Click Add, choose an unused letter (e.g. E:, F:, G:), click OK
5. Open File Explorer — the drive should now appear

macOS — Disk Utility

1. Open Disk Utility (Applications → Utilities → Disk Utility)
2. Look for your USB drive in the left sidebar
3. Select it and click First Aid → Run to check for and repair errors
4. If the drive is greyed out or won’t mount, select it and click Mount
5. If it still won’t mount, choose Erase and select exFAT for cross-platform compatibility

Fix 4 — USB keeps disconnecting and reconnecting

If your USB device connects briefly then drops out repeatedly, the cause is usually a power issue rather than a driver problem.

Disable USB selective suspend

1. Open Control Panel → Power Options
2. Click Change plan settings next to your active plan
3. Click Change advanced power settings
4. Expand USB settings → USB selective suspend setting
5. Set both On battery and Plugged in to Disabled
6. Click OK and reconnect your USB device

Use a powered USB hub

Standard (unpowered) USB hubs share the power budget from a single port. External hard drives, high-speed flash drives, and some peripherals need more power than a passive hub can deliver. Replace your hub with a powered USB hub (one with its own AC adapter) and reconnect your device.

Check BIOS/UEFI USB settings

1. Restart your PC and enter BIOS/UEFI (usually Delete, F2, or F10 during boot)
2. Navigate to Advanced → USB Configuration
3. Enable USB Legacy Support and ensure XHCI Hand-off is enabled
4. Save and exit

When the USB device itself is faulty

If you have worked through every fix above and the device still isn’t recognized on any computer, the hardware itself has likely failed.

Signs of physical failure

• The drive is not detected on any computer, including with different cables and ports
• Visible damage: bent pins, cracked casing, burn marks, or a melted smell
• The drive gets unusually hot within seconds of connection
• A faint clicking or grinding sound from a mechanical external drive

Data recovery options

If the drive contains important files that you haven’t backed up, avoid further DIY fixes — additional activity can make professional recovery harder. Data recovery services such as Ontrack and DriveSavers can recover data from physically damaged drives. For less critical cases, free tools worth trying first include Recuva (Windows) and PhotoRec (cross-platform).

Check your warranty

Most USB flash drives carry a 2–5 year manufacturer warranty. If your drive shows clear signs of hardware failure without physical damage caused by the user, check the manufacturer’s website with your drive’s model number and purchase date — you may be eligible for a free replacement.

Summary — which fix to use

Frequently asked questions

Why does my USB keep disconnecting and reconnecting?

This is almost always caused by Windows’ USB selective suspend feature cutting power to the port, or by an underpowered USB hub. Disable selective suspend in your Power Options advanced settings (see Fix 4), or replace your passive hub with a powered one that has its own AC adapter.

How do I reinstall USB drivers without losing data?

Uninstalling a USB driver in Device Manager does not delete any data on connected drives. The driver is just the software that lets Windows communicate with the hardware — uninstalling and reinstalling it is completely safe and often resolves Code 43 and Code 28 errors.

My USB is detected in Device Manager but files don’t show up — why?

The drive is recognised by Windows but hasn’t been assigned a drive letter, so File Explorer has nowhere to display it. Open Disk Management (Win + X → Disk Management), find the drive, right-click its volume, and choose Change Drive Letter and Paths → Add.

Will these fixes work on macOS?

Yes — sections covering macOS are labelled throughout the guide. The key tools on Mac are System Information (to confirm hardware detection), Disk Utility First Aid (to repair file system errors), and SMC reset (for persistent power-related issues). macOS does not require manual driver installation for standard USB devices.

Will fixing the USB error delete my data?

No — driver updates, reinstalls, and troubleshooter scans do not touch any data on the drive. The only step that risks data loss is formatting a RAW partition. If your drive shows as RAW, attempt data recovery with a tool like Recuva before reformatting.