How to fix a broken hard drive on Windows

When your external hard drive fails to show up in File Explorer or is acting strangely, there's a chance the issue is linked to a software glitch or drive letter conflict. That means you'll have trouble accessing your files.

Thankfully, there are several potential fixes to work through before concluding that the drive needs replacing entirely. According to our experts at Which? Tech Support, various Windows tools such as Disk Management and CHKDSK can help resolve the issue.

Below, we run through the steps to diagnose and resolve the issue without spending money on a professional repair service.

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Each month, we feature one of the most popular questions answered by our Tech Support team.

Question of the month: My external hard drive isn't working – what should I do?

'I have an external hard drive full of files. I’ve plugged it into my Windows laptop, but it’s acting strangely and doesn’t appear in File Explorer. I’ve tried different USB ports with no success – it seems to be faulty.

'How can I get my external hard drive working again?'

Which? Tech Support member

Our expert says:

'There are various methods you can try to fix the drive if the issue is software-related. However, if the drive has a hardware fault, such as making clicking or grinding noises, it’s best to replace it as soon as possible.

'Traditional mechanical drives (HDDs) typically last between three and five years, while solid-state drives (SSDs) can last around ten years.'

Conor Houlihan, Technical Support Advisor at Which? Tech Support

Recovering your files

Step 1: Back up your data

If you can access the data on your drive at any point before attempting to fix it, it’s best to make a backup before proceeding. A simple copy and paste to your computer or another hard drive will suffice.

Assuming you’re unable to access the drive through File Explorer and the data is important, it’s best to clone the drive, if possible, to another empty drive before attempting any repairs. The second drive should be the same size as the faulty one.

To clone your drive, do this:

1. Head to the Macrium website and download a free trial of Macrium Reflect. Note that you’ll only need the software for a few hours.
2. Install Macrium by running the downloaded file.
3. Once installed, open Macrium, select the problem drive (the source drive), and then click Clone this disk located below the drive.
4. In the window that appears, select the other empty drive. Make sure you have chosen the correct one, as the cloning process will erase all data on the destination drive.
5. Press Next, review the settings, then choose Finish and OK to start the cloning process.

Step 2: Run the Disk Management tool

You can check whether Windows is recognising your faulty external drive at the system level using the Disk Management tool.

To run Disk Management, do this:

1. Right-click the Start menu (Windows icon on the taskbar) and select Disk Management.
2. Look through the list of drives that appear in the bottom section of the window. Check to see if your external drive shows in the list – it should be identifiable by its size.
3. If your drive appears but doesn't have a letter (like F: or E:), right-click its partition (the bar next to the drive name), select Change Drive Letter and Paths, click Add, choose a letter, and press OK.
4. If your changes are accepted, the drive should now show up in File Explorer — the likely cause being that Windows didn’t automatically mount it. If the drive shows as RAW or unallocated, continue working through our guide.

If your current machine is running slow and it's beyond the help of our tips on how to speed up a slow computer, our experts have rounded up the best laptops to make upgrading a breeze.

Step 3. Check hard drive health

Most hard drives come with S.M.A.R.T. Status built in (Self-Monitoring, Analysis, and Reporting Technology). This system monitors various attributes of the drive to assess its overall health. It can help detect signs of failure early and might even identify issues before the drive becomes unusable.

To use the tool, do this:

1. Download CrystalDiskInfo – it’s a free, open-source tool.
2. Once installed, open the tool and select your drive from the toolbar by clicking Disk.
3. The tool will provide a health status and a breakdown of attributes that can help identify the source of the problem if the drive’s health is low.

Below, we've explained the key terminology related to sectors, which are the physical divisions of the drive where data is stored.

Step 4: Check for firmware updates

Most manufacturers provide firmware updates for their external hard drives. These can potentially fix or patch bugs that might cause issues, such as inaccessibility.

To access firmware updates, you can either visit the manufacturer’s website or use its dedicated update tool. Download and run the software to upgrade the firmware, then reboot and check the drive again.

For example, Seagate provides updates through its firmware update site, where you can enter your model or serial number. Western Digital (WD) offers the WD Dashboard or Kitfox tool to automatically detect and install updates. Samsung uses its Magician software to manage firmware updates.

Step 5: Run CHKDSK (check disk)

Windows has a built-in tool called CHKDSK (Check Disk) that can analyse hard drive errors and run repairs automatically. It can be a lifesaver for dealing with (non-physical) faults on your hard drive.

To try it for yourself, do this:

1. Open a new File Explorer window (on your keyboard, press the Windows key + E), then select This PC. 
2. Right-click on the drive that you wish to scan and choose Properties. The Properties window for the selected drive will now open. Here, click the Tools tab and then choose Check under the Error checking section.
3. If your PC thinks everything is running smoothly, it'll show a window stating that you don't need to scan the drive at all. However, if you'd prefer to run a CHKDSK scan, you can proceed by clicking Scan drive below this. You can't do any damage to your PC by running this scan.

For a visual walkthrough, see our full guide on how to use CHKDSK.

Step 6: Try advanced software repair

Victoria

This is a fantastic, free tool that scans your external hard drive for slow or potentially damaged sectors.

After you have downloaded Victoria, right-click on the downloaded folder and Extract. Within the extracted folder, open Victoria, select the problem drive and choose Test and Repair. Click Ignore mode and Scan to start the process. Pay attention to the colour-coded grid, where orange indicates slow sectors and red highlights bad ones.

If bad sectors appear, switch the mode to Remap and click Scan again – this tells the drive to replace bad sectors with healthy ones from its reserve. If bad sectors remain, switch to Refresh mode and click Scan – this reads and rewrites the data in those sectors if the damage is software-related.

Test disk

Another free tool that’s great for data recovery. In this instance, we’d use it to find any missing partitions. This tool should be used if the drive shows as RAW or unallocated with Disk Management. It’s slightly more technical to use, but very useful.

After downloading TestDisk, open the program and, when prompted, choose No Log and press Enter. Select the correct drive, and press Enter. Leave the partition table as the default and press Enter > Analyse > Quick search.

If a partition result appears, then press P to view a list of files to confirm it’s the right one. Once confirmed, highlight the partition and press Enter. Select Write, then hit Yes to confirm. Once complete, reboot and check File Explorer again.

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Step 7: Reformat your drive

So long as the drive shows as healthy within CrystalDiskInfo and data on the drive has been backed up, then the issue may be related to corrupted formatting. In that case, reformatting the drive can often resolve the issue. 

Do be aware this will wipe your data. So if you can back your drive up but haven't done so, you need to do this before you reformat it.

To reformat your external hard drive, do this:

1. Press the Windows key, search for Command Prompt, then right-click and select Run as administrator.
2. In the Command Prompt, type diskpart and press Enter. Then type list disk and press Enter to view all connected drives. Identify the problem drive by its size, type select disk x (replacing x with the correct disk number), then type clean and press Enter – this will remove all formatting and partitioning on the drive. 
3. Right-click the Start menu (Windows icon on the taskbar) and select Disk Management. The drive will now appear as unallocated. Right-click it, select New Simple Volume, and follow the prompts to assign a drive letter.

Once complete, the drive should be available in File Explorer and ready to use.

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