It is impossible to live without USB ports. All PCs have USB ports that you use to connect the mouse, keyboard, phone, printer and other external devices /peripherals. However, sometimes when you plug in any device you may see the USB device not recognized error.

USB Device Not Recognized

Occasionally the computer might stop recognizing USB devices. The error may sometimes behave very strangely, as the ports may work fine, but still, won’t recognize the device.

However, this error can be fixed using the below mentioned possible solutions. Some solutions might work for you.

Method 1: Unplug Computer

This is a super simple solution. All you have to do is unplug your computer from the power supply – that is all. Remember that you don’t have to just turn off your computer using the power button and then restart it. This way the computer doesn’t turn off completely and the motherboard might still be powered up. Most modern computers do that (they don’t turn off completely). This can be useful when you want to wake up the computer or something remotely.

All the hardware (that includes USB ports) of the computer is connected to the motherboard. Sometimes things can go wrong like USB ports may suddenly stop working. In this case, the motherboard has to be rebooted. When the motherboard is rebooted, the drivers are reloaded by the small microprocessor on the motherboard. That will resolve the error, and the devices may be recognized by the USB ports again.

To unplug your PC correctly, follow these steps:

  1. Click on the Shut Down option in Windows or press the power button to turn off your computer.
  2. Unplug the PC from the wall outlet.
  3. Wait for several minutes.
  4. Plug the PC into the wall outlet again.
  5. Start your computer.

 

Method 2: Update Device Driver

When the error is displayed the Windows may not be able to recognize the device. When you go to Device Manager, you will see that the device is being shown as an Unknown Device. In this case, you have to update the device driver.

To update the device driver, follow these steps:

  1. Click on Start or Press the Windows key to open the Start menu.
  2. In the search programs and files space type in devmgmt.msc.
  3. Click on devmgmt from the search results.
  4. The Device Manager window will open. Locate the Unknown Device in there.USB Root Hub
  5. Right click on the unknown device.
  6. From the available options, click on Properties.
  7. In the Properties window, click on the Driver tab.
  8. In the Driver section, click on Update Driver.Driver Section

If the USB device is just a flash drive and this method doesn’t work, then it’s probably not a driver issue. However, if the USB device is a printer, drawing pad or something like that and this method doesn’t work, then you can try downloading the driver for your device from the manufacturer’s website.

Method 3: Restart and Disconnect USB Devices

Disconnecting all USB devices and then restarting the machine can also work. When you’ve restarted your PC, connect the problem causing device. If the port you connected it to doesn’t recognize the device, try another port and then another. If a different USB port recognizes the device, then it is possible that one USB port might have a hardware problem.

However, if none of the USB ports recognize the device, then the problem is probably something else.

Method 4: USB Root Hub

Another way of fixing the USB device not recognized error is through the USB Root Hub.

To fix the problem through the USB Root Hub, follow these steps:

  1. Click on Start or Press the Windows key to open the Start menu.
  2. In the search programs and files space type in devmgmt.msc.
  3. Click on devmgmt from the search results.
  4. The Device Manager window will open. In the device manager window, locate USB Serial Bus Controllers.
  5. Click on that key to expand it.
  6. Then look for the USB Root Hub key and right click on it.USB Root Hub key
  7. From the available options, click on Properties.
  8. The properties window will open. In the properties, window click on the Power Management
  9. In the Power Management section, look for the Allow the computer to turn off this device to save power option and uncheck the box besides it.Usb Root Hub Properties
  10. If another (or more) USB Root Hub key is listed, repeat the step 6-9 for it too.
  11. After you’re done, click OK.
  12. Restart your computer.

If the USB ports still don’t recognize the device, go back to the power management tab and check the box again.

Method 5: Connect Directly to PC

If you’re using a USB hub for connecting a lot of devices, then you should try disconnecting the USB hub and connect the device directly to the computer.

Or if you can’t afford disconnecting the USB hub, as you function with a lot of external devices, then buy a new USB hub which has more power.

Method 6: USB Troubleshooter

The Windows USB Troubleshooter Fixit tool can also help you fix this error. It is a free tool that can work with Windows 7 (also Windows XP and Windows Vista).
Windows USB Troubleshooter

All you have to do is download the Windows USB Troubleshooter and let it fix the problems for you. You can also select the fixes manually and apply them. However, it is recommended to let the Windows USB Troubleshooter do its work as choosing a fix can be confusing (and pretty technical for a novice user).

Method 7: Update Generic USB Hub

You can also try another method. And this method is updating the Generic USB Hub.

To update generic USB hub, follow these steps:

  1. Click on Start or Press the Windows key to open the Start menu.
  2. In the search programs and files space type in devmgmt.msc.
  3. Click on devmgmt from the search results.
  4. The Device Manager window will open. In the device manager window, locate Universal Serial Bus Controllers.
  5. Click on that key to expand it.
  6. Then look for the Generic USB hub.
  7. Right, click on it. (If there are more generic USB hubs, right-click on the first one.)
  8. Choose Update Driver Software.Generic USB Hub
  9. The update dialog box will open. Choose the Browse my computer for driver software option in that.Browse for driver software on your computer
  10. Then look at the bottom and click on Let me pick from a list of device drivers on my computer.
  11. You will see the Generic USB Hub in the list. Select that.Select the device driver you want to install for this hardware
  12. Click on Next.
  13. Wait for the installation to finish.
  14. Click on Close.

If the USB device is still not recognized, repeat the steps 6-14 for all the other Generic USB Hubs listed.

Method 8: Uninstall USB Devices

This method should be performed as a last resort.

Sometimes the Windows fails to automatically recognize the USB controllers, devices, and hubs, so no USB ports work. In this case, you have to uninstall all USB devices from your system.

To uninstall all USB devices from your system, follow these steps:

  1. Click on Start or Press the Windows key to open the Start menu.
  2. In the search programs and files space type in devmgmt.msc.
  3. Click on devmgmt from the search results.
  4. The Device Manager window will open. In the device manager window, locate USB Serial Bus Controllers.
  5. Click on that key to expand it.
  6. Then uninstall each item under the USB Serial Bus Controllers key.

USB Serial Bus Controllers

First of all, uninstall the items that have exclamation points or are listed as Unknown Device.

Method 9: Uninstall Hidden Devices

The Device Manager, by default, doesn’t show all installed devices. The devices it shows are the ones that are currently connected. So if you were using a USB printer anytime earlier, it would be still installed, but won’t show up.

These hidden or ghost USB devices can cause conflicts with the current USB devices that may be causing the error.

To uninstall hidden devices, follow these steps:

  1. Open Command Prompt as administrator. If you don’t know how to do it, then go to the Start Type cmd in the Start menu and then press Enter. From the search results, right-click on Command Prompt and select run as administrator.
  2. When the black window of the Command Prompt opens, type the following commands:

set DEVMGR_SHOW_DETAILS=1

set DEVMGR_SHOW_NONPRESENT_DEVICES=1

startdevmgmt.msc

Command Prompt

  1. The Device Manager window will open. In the Device Manager window, click on View.
  2. Then click on Show Hidden Devices.Device Manager
  3. Then click on Imaging Devices, Unknown Devices, and Universal Serial Bus Controllers to expand them.
  4. Look for anything highlighted gray or that says unknown device.
  5. If you find any, right-click on it and uninstall it.