Plugged your external hard disk drive into your computer and noticed it's slower than it used to be? If you use the drive regularly, this could be easily explained: perhaps it's slowing down because it's old or needs defragging.

But if the drive is only occasionally used, and you've just spotted the speed issue, there's a chance it might be related to something else. Could your PC have a virus? Is there a setting in Windows 10 that is slowing things down? Or could the problem be something as simple as changing cables?

Let's find out.

Is Your External Hard Disk Drive Slower Than Before?

If your external hard disk drive's performance has decreased, several steps can be performed to either diagnose the problem or repair it.

  1. Defragment your disk drive
  2. Run a check disk scan
  3. Look for damage to the case or the drive itself
  4. Check the cables, replace if necessary
  5. Too much disk activity
  6. Check your drive and PC for viruses and malware
  7. Disable Windows indexing for faster performance

The rest of this article will show you exactly how to do each of those steps. However, should none of these fixes work, then it's probably a good time to consider a new external HDD.

The sooner you do this and are able to copy the data from your old device, the better. Leave it too late and data on the old HDD may be completely irretrievable.

1. Defrag Your Slow External Hard Drive

Whenever you experience hard disk issues, one of the first things you should do is defragment your drive. Windows 10 features the Defragment and Optimize Drives tool. To use this:

  1. Click Start
  2. Type "defragment" or "optimize"
  3. Click Defragment and Optimize Drives
  4. Select the troublesome drive
  5. Select Analyze
  6. Wait while it completes
  7. If action is required, click Optimize

Remember, these instructions are mainly intended for traditional hard disk drives rather than solid state drives (SSDs).

On older versions of Windows, SSDs should not be used with standard defragmentation tools. As SSDs are flash-based, older defrag tools are likely to damage your data, if not the disk itself.

Fortunately, Windows 10 does not have this problem. The Defragment and Optimize Drives tool manages the optimization of SSDs as well as HDDs.

2. Run a Check Disk Scan

If the defrag completes successfully but there is no improvement from your HDD, try the Check Disk tool. This is a tool that dates to early versions of Windows. It's capable of detecting (and sometimes repairing) problems with a hard disk drive. This often includes damaged sectors, which can lead to corrupt data.

You have two options to run Check Disk:

  1. Right-click the drive letter in Windows Explorer and select Properties > Tools then look for "Error checking". Here, click Check and follow the instructions.
    Check your hard disk if performance is slow
  2. Check Disk can also be run in the Windows PowerShell (Admin). Access this by right-clicking the Start button.

Once running, input:

        chkdsk.exe /f [DRIVE_LETTER]
    

Make sure you input the drive letter of the disk drive (or partition) that is causing you problems.

Check Disk often requires you to reboot Windows, so ensure you have closed all your applications beforehand.

3. Check Your Slow Hard Drive for Physical Damage

If you've made it this far with no improvement, there's a possibility that your HDD is damaged. You should take the time to check the disk carefully, paying special attention to the following:

  • Does the LED light flash or not?
  • Does the computer hang when you attempt to browse the disk?
  • Does Check Disk fail?
  • Is the disk rattling when you hear it spin?

Although protected by the drive enclosure, hard disks are delicate, regardless of the bulky appearance. Not only can the disks themselves be damaged by a slight knock, so too can the read heads.

Meanwhile, the small slivers of circuit board are delicate and sensitive to contact. Even screwing a hard disk drive into an enclosure, PC, or laptop too tightly can result in problems.

If slower performance is traced to a damaged HDD, you should arrange a replacement ASAP. If you're likely to have this problem again in the future, it might be worth buying a tougher, durable portable HDD.

4. Check the Disk Drive Cables for Wear and Tear

Another problem that can cause the disk to respond poorly is worn cables. With the external HDD disconnected from your computer and the wall, examine the USB cable and power lead.

Any cracks in the rubber insulation can often indicate a damaged cable inside. Cables with broken or damaged connectors (splitting, or hanging off) meanwhile should be discarded immediately.

If these problems occur with a power cable, you're dicing with death. Meanwhile, if the USB cable is evidently damaged, this could be why your disk is not responding.

Replacement USB cables are inexpensive. Just make sure you buy the right type for your external HDD; modern devices are almost all USB 3.0, while older ones will be USB 2.0.

While we're discussing USB ports, it's also worth checking if your external HDD works when connected to a different port. Sometimes one port will work better than another. Alternatively, you might be using a USB 3.0 device in a USB 2.0 port, which often doesn't work well. USB 3.0 devices are limited to the speed of a USB 2.0 port, so connect USB 3.0 devices to corresponding ports.

5. Is Too Much Activity Slowing Your Hard Disk?

If you're copying large quantities of data to or from your computer, this can result in a slow external drive.

For instance, you might be copying huge video files from your PC to the drive. Or you might be using it as a destination drive for torrent files. Either way, if large amounts of data are involved, an external HDD (or an internal one) can slow down considerably.

To find out if this is the case, use the Task Manager.

  1. Launch Task manager using Ctrl + Shift + Esc or right-click the Taskbar and select Task Manager.
  2. Click the Disk column header to sort applications by disk utilization.
Check Task Manager for slow disk performance

If the answer is Windows Explorer, then the problem is due to copying data. But you could be using a torrent app, or image or video editing tool. You might even be running a video game from a USB 3.0 drive. Whatever the app is, select it and click End task to stop it. This will hopefully return the drive to its usual working speed.

Noticed a lot of disk activity, perhaps as much as 100 percent? This is a known Windows 10 bug, which has its own set of solutions.

6. Are Viruses and Malware Slowing Your External Hard Drive?

It can never be said regularly enough: you should be running an active antivirus tool on your computer. Even if you're not, you should have a tool that you can use to run malware scans.

Check out our list of the top online security suites for help.

Whatever the case, a rogue script could be accessing your hard disk drive and slowing it down. Worse still, the script (what we would usually term malware) might be already on your external hard drive. The slowdown isn't from the disk itself, but your PC or laptop. Literally, the external hard drive is slowing down your Windows 10 computer.

To scan a drive:

  1. Open Windows Explorer.
  2. Right-click the drive.
  3. Find the antivirus or malware scanning software in the context menu.
  4. Select the option to scan the disk.

If this option isn't available, open the security software and manually scan the disk. The method for this differs depending on your chosen security software

Note that this may not be possible with Windows running normally; you may have to reboot into Safe Mode.

7. Is Windows 10 Indexing Slowing Your External Hard Drive?

Finally, you could kick your slow external HDD back into life by disabling Windows 10's indexing service. Often when you connect your HDD to your PC, Windows takes forever to display its contents in Explorer. The reason is that Windows 10 is busy indexing the drive.

Disabling indexing stops this and speeds things up. The drawback is that Windows search will be limited to filenames, rather than metadata. This will reduce the speed of finding files on your drive if you don't know the filename.

To disable indexing:

  1. Press Windows + R.
  2. Enter "services.msc".
  3. Click
  4. In the Services window scroll down to Windows Search.
  5. Right-click and select
  6. Click Stop.
  7. Wait for this to complete.
  8. Click Startup type > Disabled.
Windows disk indexing can slow HDDs

Disconnect and reconnect your external hard disk drive and open it in Windows Explorer. It should now load quickly as if it was an internal drive.

Fix Your Slow External Hard Drive!

Following these steps from beginning to end should help to resolve your external hard disk drive issues. For newer drives, disabling Windows 10's indexing feature is often the most effective solution.

A slow external hard drive is one problem. What if your external hard drive is not even recognized? There are fixes for that too.