Summary

This article provides step-by-step methods to diagnose and fix USB devices that are not recognized, stop working, or disconnect intermittently on Windows — including flash drives, external hard drives, keyboards, mice, and webcams.

In this guide

• 1. Try Basic Physical Checks First
• 2. Restart Your Computer
• 3. Run the Windows Hardware Troubleshooter
• 4. Reinstall the USB Device Driver
• 5. Disable USB Selective Suspend
• 6. Safely Eject USB Storage Devices
• 7. Format a USB Drive That Is Not Readable
• 8. Escalation — When to Contact IT

Before You Start

• Windows 11 or Windows 10.
• The USB device and a USB cable (if applicable).
• At least one working USB port on your computer.
• No admin rights are required for most steps in this article.

Instructions

1. Try Basic Physical Checks First

Many USB issues are caused by loose connections, faulty cables, or unpowered hubs.

1. Unplug and replug the USB device. Remove it, wait 10 seconds, and plug it back in firmly.
2. Try a different USB port. If using a front panel port, try a rear port instead. If using a USB hub, try connecting directly to the computer.
3. Try a different cable if the device uses a detachable cable.
4. Test the device on another computer. If it fails there too, the device itself may be defective.
5. Check the USB hub. Ensure powered hubs are plugged into a wall outlet — some devices need more power than a passive hub provides.

Verification: If the device works in a different port or on a different computer, the issue is with the original port or your computer's USB configuration.

Note: Storage devices have their own failure modes on top of these. If an external hard drive or SSD powers up but never appears in File Explorer, follow How to Fix an External Drive Not Showing Up on Windows instead — it covers missing drive letters, Mac-formatted disks, and when to stop troubleshooting to protect the data.

2. Restart Your Computer

A restart clears the USB host controller state and reloads all device drivers.

1. Save any open work.
2. Unplug the problem USB device.
3. Click Start > Power > Restart (use Restart, not Shut down).
4. After the computer restarts, plug the USB device back in.
5. Wait 15–30 seconds for Windows to detect and configure the device.

Note: Use Restart, not Shut down. Windows 11 uses Fast Startup by default, so a shut down does not fully reset the USB controller state.

3. Run the Windows Hardware Troubleshooter

Windows includes a built-in troubleshooter that detects and fixes common USB problems.

1. Press Windows + I to open Settings.
2. Click System > Troubleshoot > Other troubleshooters.
3. Find Hardware and Devices and click Run.
4. Follow the on-screen instructions. The troubleshooter scans and applies fixes automatically.
5. After the troubleshooter completes, replug the USB device and test.

Tip: If you cannot find the troubleshooter in Settings, press Windows + R, type msdt.exe -id DeviceDiagnostic, and press Enter.

4. Reinstall the USB Device Driver

A corrupted or outdated driver can prevent Windows from recognizing a USB device.

1. Press Windows + X and select Device Manager.
2. Expand the relevant section:
   • Universal Serial Bus controllers — USB hubs and root hubs.
   • Disk drives — USB flash drives and external hard drives.
   • Unknown devices or Other devices — devices with missing drivers (yellow ⚠️ icon).
3. Right-click the problem device and select Uninstall device.
4. Check Attempt to remove the driver for this device if available, then click Uninstall.
5. Unplug the USB device.
6. Click Action > Scan for hardware changes in the Device Manager menu.
7. Plug the USB device back in. Windows reinstalls the driver automatically.

Verification: The device appears in Device Manager without a yellow warning icon. Storage devices also appear in File Explorer.

5. Disable USB Selective Suspend

Windows may put USB ports into low-power mode, causing devices to disconnect intermittently.

1. Press Windows + I to open Settings.
2. Click System > Power & battery > Additional power settings.
3. Click Change plan settings > Change advanced power settings.
4. Expand USB settings > USB selective suspend setting.
5. Set both On battery and Plugged in to Disabled.
6. Click Apply > OK.
7. Replug the USB device and test.

Note: Disabling selective suspend may slightly increase battery usage on laptops.

6. Safely Eject USB Storage Devices

Always safely eject USB storage devices before unplugging to avoid data corruption.

1. Click the Safely Remove Hardware icon in the system tray (near the clock). Click the up arrow (^) if hidden.
2. Click Eject [Device Name].
3. Wait for the "Safe to Remove Hardware" notification.
4. Physically unplug the USB device.

Alternative method:

1. Open File Explorer, right-click the USB drive under This PC, and select Eject.

7. Format a USB Drive That Is Not Readable

If a USB flash drive shows "You need to format the disk", reformatting restores it to a usable state.

1. Open File Explorer > This PC.
2. Right-click the USB drive and select Format.
3. Choose a File system: NTFS (Windows-only, large files), exFAT (cross-platform), or FAT32 (maximum compatibility, 4 GB limit).
4. Enter a Volume label, check Quick Format, and click Start.

WARNING

Formatting erases all data on the drive permanently. If the drive contains files you need, stop here and ask IT to attempt recovery before you format — tell them the drive letter, roughly what was stored on it, and the exact prompt Windows showed you.

8. Escalation — When to Contact IT

Some USB faults need driver-installation rights you do not have. A ticket that names the device's make and model, quotes the text under any yellow warning icon in Device Manager, and lists which ports and computers you already tried gives IT enough to diagnose it without borrowing your machine.

Contact your IT team if the device fails on multiple ports and computers, Device Manager shows persistent yellow warning icons after driver reinstall, you need manufacturer-specific drivers requiring admin rights, or multiple USB ports have stopped working simultaneously.

Troubleshooting

DANGER

Always try Method 1 (physical checks) and Method 2 (restart) before anything else. Most USB issues are caused by loose connections, unpowered hubs, or a stale USB controller state.

Symptom / Error	Potential Cause	Solution
"USB Device Not Recognized"	Corrupted driver or faulty port	Try a different port. Reinstall the driver via Device Manager (Method 4).
Device connects and disconnects repeatedly	USB selective suspend or insufficient power	Disable USB Selective Suspend (Method 5). Use a powered hub or connect directly.
"You need to format the disk"	File system corruption	Format the drive (Method 7). If the data matters, ask IT to attempt recovery first — tell them the drive letter and what was stored on it.
USB mouse or keyboard unresponsive	Driver conflict or port issue	Plug into a different port. Reinstall the driver (Method 4). Restart the computer.
Device works elsewhere but not on my PC	USB controller or power issue	Restart (Method 2). Disable Selective Suspend (Method 5). Run the troubleshooter (Method 3).
"Cannot eject — device is in use"	Files or apps still accessing the drive	Close all files and Explorer windows for the drive. Wait 30 seconds and retry.

Related Articles

• How to Fix an External Drive Not Showing Up on Windows
• How to Fix Common Computer Glitches by Restarting
• How to Troubleshoot Bluetooth Device Issues (No Admin Required)
• How to Troubleshoot Apps That Won't Open or Keep Crashing on Windows
• How to Manage Startup Apps in Windows 11
• How to Troubleshoot External Monitor Issues (No Admin Required)

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