When you try to access data on an external USB hard drive, you may receive the following error:

"USB Device not recognized: One of the devices attached to this computer has malfunctioned and windows does not recognize it."

Cause

This issue can be caused if any of the following situations exist:

• The currently loaded USB driver has become unstable or corrupt
• Your PC requires an update for issues that may conflict with a USB external hard drive and Windows
• Windows may be missing other important updates hardware or software issues
• Your USB controllers may have become unstable or corrupt
• Your external drive may be entering selective suspend
• Your PC motherboard may need updated drivers

To resolve this issue, follow the steps in the methods below in the order listed. If the first method does not fix the problem, proceed to the next.

Method 1: Uninstall and then reconnect the external hard drive

This method resolves issues where the currently loaded USB driver has become unstable or corrupt.

1. Select Start, type Device Manager in the Search box
2. Select Device Manager from the returned list.
3. Select Disk Drives from the list of hardware
4. Press and hold (or right-click) the USB external hard drive with the issue, and select Uninstall.
5. After the hard drive is uninstalled, unplug the USB cable.
6. Wait for 1 minute and then reconnect the USB cable. The driver should automatically load
7. Check for the USB drive in Windows Explorer

Note Connecting your USB external hard drive into a non-powered USB hub can cause a lack of enough power to operate the external drive. Instead, plug it directly into your computer.

If this method does not resolve your issue, proceed to Method 2.

Method 2: Install Hotfixes that resolve issues that may exist on Windows 7

The hotfixes in this method can resolve a known conflict with a USB external hard drive and Windows.

1. Go to KB 976972 You encounter problems when you move data over USB from a Windows 7 or Windows Server 2008 R2-based computer that has an NVIDIA USB EHCI chipset and at least 4GB of RAM.
2. Under Update information, select Download the update package now that corresponds with your version of Windows 7. 
   1. If you're unsure of which version of Windows 7 you are running, select the Start button, press and hold (or right-click) Computer > Properties.
      • If "64-bit Operating System" is listed next to System type, you’re running the 64-bit version of Windows Vista or Windows 7.
      • If "32-bit Operating System" is listed next to System type, you’re running the 32-bit (x86) version of Windows Vista or Windows 7.
3. Select Continue. If a User Account Control permission, select Yes.
4. Select Download > Open.
5. The download should start in 30 seconds. If it does not, select Start Download > Open.
6. Follow the onscreen instructions to complete the download and installation.
7. Go to KB 974476 The computer stops responding when an USB device resumes from the USB Selective Suspend state in Windows 7 or in Windows Server 2008 R2
8. Select View and request hotfix downloads > Select hotfix.
9. If prompted, review the license agreement. If you agree to the terms, select I Accept.
10. Check the box next to your version of Windows 7, then enter your email in the boxes below.
11. Enter the word verification, then select Request hotfix.
12. Check your email. You will soon see an email from Microsoft with a download link for the hotfix. Selet the link and follow the onscreen instructions to download and install the hotfix.
13. Restart your computer.

If your problem still persists, proceed to Method 3.

Method 3: Install the latest Windows Updates

This method will install the latest device drivers for your USB external hard drive.

1. Select the Start button, type Windows Update in the Search box, and then select Windows Update in the results pane.
2. Select Check for Updates. After the scan is complete, select Review optional updates.
3. Select the check box next to the updates, then select Install updates.
4. If prompted, review the license agreement, then select I Accept.
5. Follow the onscreen instructions to download and install the updates.
6. If prompted, reboot your computer.

If your problem still exits, proceed to Method 4.

Method 4: Reinstall USB controllers.

This method resolves steps where the currently loaded USB driver has become unstable or corrupted.

1. Select Start, then type device manager in the Search box, and then select Device Manager.
2. Expand Universal Serial Bus controllers. Press and hold (or right-click) a device and select Uninstall. Repeat for each device.
3. Once complete, restart your computer. Your USB controllers will automatically install.

If your problem still exists, proceed to Method 5.

Method 5: Disable USB selective suspend setting.

This method prevents your USB external drive from powering down.

1. Select the Start button, type power plan in the Search box, and then select Choose a power plan.
2. Next to your currently selected plan, select Change Plan Settings.
3. Select Change advanced power settings.
4. Select the box to expand USB Settings > USB selective suspend settings.
5. Select Plugged in, select the drop down menu, and then select disabled.
6. If you're using a laptop, select Battery, select the drop down menu, and then select disabled.
7. Select Apply > OK.

If this doesn't resolve your issue, proceed to Method 6.

Method 6: Install your motherboard's latest chipset drivers.

This method updates your motherboard's chipset drivers, so your computer will recognize your USB external hard drive.

1. Review your computer's documentation which should contain the name of the motherboard manufacturer.
2. Visit your computer manufacturer's support website. For a list of computer manufacturers' support sites, see Computer manufacturers' contact information.
3. Navigate their website to find the appropriate drivers for your motherboard. For assistance, contact your computer manufacturer.

If your issue still exists, we recommend contacting Microsoft product support. For information on how to get assistance from Microsoft, see Products.

For more information about Windows Update, visit: http://windows.microsoft.com/en-US/windows7/products/features/windows-update