USB Device Not Recognized — How to Fix Port and Driver Issues

Overview #

When you plug in a USB drive, keyboard, or camera and see the message “USB device not recognized,” it usually means there is a communication problem between your computer and the device.
The cause can be a faulty cable, an unresponsive USB controller, or outdated drivers. This guide walks you through a set of safe, proven steps to get your USB ports working again.

What you’ll learn

• How to verify power delivery to USB ports
• How to reset or reinstall USB controllers
• How to check for device or cable faults
• How to test system-level power and driver settings

Estimated time: 10–15 minutes
Skill level: Beginner to Intermediate

---

Terms and Definitions #

Term	Meaning
USB Controller	Hardware that manages all USB connections in your computer
Driver	Software that allows your operating system to communicate with hardware
Power Surge	A temporary overcurrent that shuts down a USB port to prevent damage
Hub	A device that expands one USB port into several additional ports

---

Steps #

Step 1 — Check the Physical Connection #

Begin with a simple hardware check.

1. Unplug and reconnect the device securely.
2. Try a different USB port, ideally on the opposite side of your laptop or a rear port on a desktop.
3. Avoid using hubs or adapters for now; connect the device directly to the computer.

If the device suddenly works, the issue lies in the hub or port you were using.

---

Step 2 — Power Cycle the Computer #

Rebooting clears temporary power faults in USB controllers.

1. Unplug all USB devices.
2. Shut down the computer completely.
3. Disconnect the power cord (and battery if removable).
4. Wait 30 seconds, then reconnect power and start the system.
5. Plug in the USB device again and test.

If it now appears, the controller reset itself successfully.

---

Step 3 — Check USB Power States #

Windows PowerShell

Get-PnpDevice -Class USB | Select-Object FriendlyName, Status

Displays a list of connected USB devices and whether each is active or disabled.

macOS Terminal

system_profiler SPUSBDataType

Shows all connected USB devices, their manufacturers, and power draw.

If a device shows “Status: Disabled” or “Current Required” greater than “Current Available,” the system has turned off that port to protect hardware.

---

Step 4 — Reset the USB Controller #

Windows

1. Open Device Manager.
2. Expand Universal Serial Bus Controllers.
3. Right-click each entry labeled “USB Root Hub” or “Generic USB Hub” and select Uninstall device.
4. Restart the computer; Windows will reinstall them automatically.

PowerShell Alternative

Get-PnpDevice -Class USB | Disable-PnpDevice -Confirm:$false
Get-PnpDevice -Class USB | Enable-PnpDevice -Confirm:$false

Disables and re-enables all USB devices to refresh the controller.

macOS

sudo kextunload /System/Library/Extensions/IOUSBHostFamily.kext
sudo kextload /System/Library/Extensions/IOUSBHostFamily.kext

Restarts the macOS USB subsystem. This requires administrator privileges.

---

Step 5 — Update USB Drivers #

Windows

Get-WindowsDriver -Online | Where-Object {$_.Driver -like "*USB*"}

Lists current USB drivers.
If any are outdated, right-click in Device Manager and choose Update driver, or download the latest version from your computer manufacturer’s support site.

macOS

softwareupdate -l
softwareupdate -i -a

macOS updates its USB drivers through system updates. Install all available updates to ensure compatibility.

---

Step 6 — Adjust Power Management Settings #

Windows sometimes disables ports to conserve power.

Windows PowerShell

powercfg -devicequery wake_from_any

Shows which devices can wake the computer. If your USB device is missing, the port may be powered down.

To fix this:

1. Open Device Manager → USB Root Hub → Properties → Power Management.
2. Clear the checkbox labeled “Allow the computer to turn off this device to save power.”

---

Step 7 — Test the Cable or Device #

To confirm whether the problem is with the port or the device:

1. Connect another USB device to the same port.
2. Try the problem device on a different computer.

If another computer recognizes it, the fault is local to your system.
If no computer recognizes it, the device or cable is defective.

---

Step 8 — Check Event Logs for USB Errors #

Windows PowerShell

Get-EventLog -LogName System -Newest 20 | Where-Object {$_.Message -like "*USB*"} | Format-Table TimeGenerated, Message -AutoSize

Lists the last twenty USB-related system events.

macOS

log show --predicate 'subsystem == "com.apple.usb" && eventMessage CONTAINS "error"' --last 1h

Displays USB-related errors recorded in the last hour.

Review these logs to determine if there are recurring connection or power issues.

---

Verification #

After completing the steps:

1. Reconnect the USB device.
2. Confirm that it appears in File Explorer (Windows) or Finder (macOS).
3. Check that Device Manager or system_profiler lists the device as active.
4. Confirm that there are no yellow warning icons or repeated error logs.

If all checks pass, your USB ports and drivers are functioning correctly.

---

Conclusion #

You have systematically reset the USB subsystem, verified drivers, and tested both hardware and power settings.
Most recognition errors stem from either a power management feature disabling the port or a driver failure.
If the problem reappears even after these steps, it likely indicates a failing USB controller or damaged port that may need professional repair.
By following this guide, you’ve eliminated all common software causes and confirmed whether the issue is electrical or physical.