How to Fix a Corrupted External Hard Drive and Recover Your Data

If your external drive slows down, files randomly disappear, or Windows keeps throwing errors when you try to access it, it may be corrupted. Even though the average life span of an external HDD is about three to five years, from what we’ve seen it doesn’t always mean the story ends there. Most of the time, you can repair a corrupted external hard drive and save your files, and today we’ll break down how to do it in plain language.

How External Drive Corruption Usually Shows Up

Before we jump into fixes, it’s worth pointing out how corruption usually shows up. A lot of people don’t realize the signs until the drive fully gives up, so spotting them early can make a difference. Sometimes the symptoms are obvious, other times they’re more subtle.

Here’s what you might see:

How to Recover Data From a Corrupted External Hard Disk

To recover files from a corrupted external hard drive, you’ll need to use third-party data recovery apps. But, you can only do this if the corrupted external hard drive is detected by your PC. To check this, press Windows Key + R, type diskmgmt.msc, and press Enter. In the Disk Management window, see if your external hard drive is visible.

If it’s visible and doesn’t have the No Media label, you can proceed with the data recovery process. If not, it’s likely that your drive is physically damaged or has severe logical corruption to the extent that it needs to be examined by a professional data recovery service.

When we talk about corrupted external hard drive recovery, we mean a two-step process:

• First, you create a disk image of the corrupted external hard drive. This is important, as direct scans are stressful to the drive and may worsen the data loss. A disk image is essentially a virtual copy of your entire drive, and it can be scanned without risking your physical drive.
• Second, you scan that image with recovery software to pull your files back.

A quick Google search will reveal that numerous data recovery programs claim to recover your data. You’re spoiled for choice. Why recovery software in the first place? Because when a file system is damaged, there’s virtually no other practical way to extract your data. More importantly, these tools work. Based on our own data loss survey, nearly 80% of users who tried reputable recovery software were able to restore their data successfully.

Let’s see how you can restore data from a corrupted external HDD:

Step 1: Create a Disk Image of the External Hard Drive

1. Download Disk Drill and install it.
2. Connect the corrupted external HDD to your PC.
3. Open Disk Drill and click on the Byte-to-byte Backup option under Extra Tools.
4. Select the corrupted external HDD from the device list and click on Create backup.
5. Choose a save destination for the disk image. Remember, it must have enough free space that is equal to or more than the entire storage size of your external HDD. Click OK.
6. Disk Drill will create the disk image. This may take a while, depending on your external drive’s storage size and your PC’s specs.

Step 2: Scan the Disk Image of the External Hard Drive

Now that your image file is ready, you can scan it the same way you would scan a regular disk.

1. Open Disk Drill, and make sure you’re on the Storage Devices screen.
2. Click on the Attach disk image option. Browse for the disk image you’d created earlier and double-click on it. It’ll be mounted to Disk Drill and show up as a storage drive.
3. Select your external HDD’s disk image and click Search for lost data.
4. If the app asks you to choose a scan mode, go with Universal Scan.
5. Click Review found items to view the recoverable files on your drive. You can directly click on the file type you wish to restore, such as Pictures, Video, Audio, Documents, Archives, and Other.
6. Expand the Existing tab to view files that are present on the external HDD. To view deleted files, expand the Deleted or lost, and Reconstructed sections. Then use the checkboxes to select the desired files and folders. Disk Drill will display a preview of the currently selected file. If you don’t see the preview on the right, click the little eye icon next to the file name – it’ll pop up instantly. Not only is this convenient for sorting through your results, but it also gives you 100% certainty that the file is fine and can be recovered fully intact. If it plays, opens, or looks right in preview, you’re good to go.
7. Click Recover once your selection is complete.
8. Choose a recovery destination for your files (make sure it’s a different drive) and click Next.
9. Disk Drill will recover your files. You can retrieve up to 100 MB of data for free with the trial version, which is usually enough to test how well it works, or even recover your most important files, like work documents, photos, or small videos without paying.

How to Fix a Corrupted External Hard Drive

In most cases, you can fix a corrupted hard drive without formatting. The only exception is extensive damage to the drive’s file system.

We’ll show you 4 methods to fix a corrupted external hard drive. Some of them are complex, so be sure to follow the instructions carefully.

Method 1: Inspect the Drive

If you noticed the corruption on your drive after it was dropped or suffered any other form of physical impact, you need to perform a physical examination of the drive.

Here are two things you can do:

• 🔉 Check for any clicking, whirring, or beeping sounds from the drive. If you notice these sounds, your drive’s internal components are damaged. Stop using the drive and contact a professional data recovery service.
• 🔌 Check the cable and the connectors on your hard drive. If you see any sort of damage, such as a stretched wire or a broken port, you’ll need to dismantle the external hard drive and connect it to your PC using a SATA cable. Only do this, if you’re comfortable working with PC hardware. Otherwise, use a professional data recovery service. Remember, you can lose your data if you mishandle the drive physically and damage its platter in any way.

Method 2: Repair the Corrupted Partition on External Hard Drive

If you have trouble accessing your external hard disk’s partition, and you get errors such as the “access is denied” message, the partition could be corrupt. It may not show up in File Explorer as well. Additionally, a corrupt boot sector could be causing your drive or a specific partition to show up as RAW on your PC.

Fortunately, there’s a solid open-source tool you can use to fix this: TestDisk. It’s free, widely trusted, and we’ve used it more times than we can count. It’s not perfect, and it doesn’t work in every single case, but we’ve seen it recover partitions on external hard drives with a pretty high success rate.

The only drawback is that it doesn’t have a GUI, so navigating within the program is a little difficult for new users.

We’ll show you two ways you can use TestDisk to recover a corrupted external hard drive:

Option A: Use TestDisk to Repair a Corrupt Partition

First, you can try to restore the lost partition – it may have been removed or corrupted in a way that makes the drive unreadable but still recoverable. Here’s what to do:

1. Download TestDisk. Extract the contents of the archive and run the testdisk_win.exe file.
2. Choose whether you want to create a log or not. Use the arrow keys to navigate and the Enter key to confirm.
3. Select the corrupted external hard disk and press Enter to confirm.
4. Select the partition table type. It’s recommended you simply press Enter on this screen, because TestDisk automatically detects the partition table type.
5. Select Analyse and press Enter.
6. Select Quick Search and press Enter.
7. Use the left and right arrow keys to cycle through the partition type. Make sure there is a P right at the beginning, as shown in the image below. Press Enter.
8. Highlight the Write option, and press Enter.
9. Press Y on the confirmation prompt.
10. TestDisk will recover the corrupted partition.

Option B: Repair the Corrupted Hard Drive’s Boot Sector Using TestDisk

Another way you can use TestDisk is to repair the boot sector on your external hard drive.

The boot sector is a tiny section at the very beginning of a partition that tells the system how to read the file system. If it gets corrupted, Windows can’t figure out what to do with the data. But the files are often still there; it’s just that the system doesn’t know how to access them. Here’s what to do:

1. Open TestDisk and choose whether you want to create a log file or not.
2. Select your drive and press Enter.
3. Press Enter on the partition table selection screen.
4. Highlight Advanced and press Enter.
5. Select the partition that’s showing up as RAW on your PC.
6. Select Boot and press Enter.
7. Finally, select Rebuild BS and press Enter. On the next screen, pick Write and press Enter. Reboot your PC and you should be able to access the corrupted hard drive.

Method 3: Fix Corrupted Hard Drive Errors

Windows has an in-built utility that can detect and resolve file system errors on your external hard disk – CHKDSK. While CHKDSK is a command line utility, you can run a basic GUI version of it using File Explorer. It’s simply labeled as the Error Checking Tool.

Two things to keep in mind when using CHKDSK or the Error Checking Tool:

• CHKDSK only works if Windows can detect your drive and recognize its file system (it won’t work on RAW drives).
• Restore your data before you run these utilities. In some cases, they may delete files from your drive.

Let’s take a look at both ways to fix errors on your corrupted hard drive:

Option A: The Disk Error Checking Tool

Here’s how to use it:

1. Connect your corrupt external hard disk to your PC.
2. Open Windows Explorer (Windows Key + E).
3. Right-click on the external hard drive and choose Properties. 
4. Click on the Tools tab, and under Error checking, click Check.

Option B: CHKDSK

CHKDSK isn’t quite as straightforward as Error Checking, but it’s still nothing too complex. Here’s how to use it:

1. Type “cmd” in Windows Search (Windows Key + S). Right-click on Command Prompt > Run as administrator in the search results.
2. Type chkdsk X: /f and press Enter. Replace X with the drive letter of your external HDD.
3. The process may take some time, depending on the size of your HDD.

Method 4: Repair Bad Sectors on the External Hard Drive

Bad sectors are parts of your drive that have become unreadable. These can happen with age, wear, or after physical damage or power loss. When your drive hits one of these bad blocks, it may freeze, slow down, or fail to copy or open files. Some bad sectors are purely logical and fixable with software. Others are physical  (permanent), but you can still mark them as unusable so the system skips them.

We’ll show you two ways you can try to repair bad sectors: one using a third-party tool called Victoria, and another using the good old full formatting method.

Option A: Victoria

Victoria has been around for a long time and is still one of the best free tools for bad sectors. It gives you a clear view of how your external hard drive is doing at the hardware level.

Here’s how to use Victoria:

1. Download the app.
2. Once you open it, make sure your external hard drive is selected in the list. You should see its model, capacity, and status info.
3. Click on the Test & Repair tab at the top. This is where all the sector-level scanning and repair options are. Make sure the drive isn’t being accessed by other programs.
4. Use the Scan button to begin scanning. You’ll start seeing colored blocks appear in the grid area – each color represents a response time: green is normal, yellow/orange means slow sectors, red means bad (unreadable) blocks.

After the scan, if you see mostly green and a few isolated yellow sectors, your drive is still usable (but it’s a sign of aging). It’s not perfect, but it should be okay for light use or as a second backup.

That said, if you start seeing a lot of red blocks, that’s a different story. You should seriously rethink using this drive for anything important. It’s not something you can trust for active storage anymore.

Option B: Full Formatting

If you don’t want to use third-party tools like Victoria, you can try a full format instead. Windows lets you do two kinds of formatting – a Quick Format (which is the default and recoverable) and a Full Format.

The full format takes longer, but it does a deeper scan of the drive. It checks each sector and marks any bad ones so they won’t be used again. This doesn’t actually repair the damaged sectors, but it helps prevent future crashes by isolating the problem areas.

Here’s how you can perform a Full Format in Windows:

1. Press Windows Key + R, and type diskmgmt.msc in the Run text box. Press Enter.
2. In Windows Disk Management, right-click on your external hard drive and click Format.
3. In the Format options window, uncheck the Perform a quick format option. This is important. Click OK.

We usually recommend full formatting only as a last resort, after you’ve tried recovery and saved data. But if the drive has no hardware issues and the corruption was strictly logical, a full format is still the most reliable way to get your external hard drive back in working order. It’s a clean reset that clears all logical problems in one go.

Can I Trust This External Drive from Now On? (Let’s Talk S.M.A.R.T.)

We already mentioned S.M.A.R.T. earlier, but now let’s go into more detail. If you’re wondering whether you can keep using this drive long-term, this is where you look.

The good news is: you don’t need to be an engineer to check them. Most tools display S.M.A.R.T. data in a simple way: good or bad, often color-coded in green/yellow/red. You’ll also see values, thresholds, and sometimes “raw” numbers. Some popular tools for reading this on Windows include: CrystalDiskInfo, GSmartControl, SpeedFan. And like we already mentioned, some recovery apps, such as Disk Drill, include built-in S.M.A.R.T. as an extra.

What to Look For

One of the most important attributes is Reallocated Sector Count. That tells you how many sectors have gone bad and were replaced with spare ones. If this number is zero, you’re probably okay. If it’s above zero, it doesn’t mean the drive is dead – but it does mean the risk of failure is higher than average.

Google did a well-known study (you can find it here) showing that even a single reallocated sector can raise the chance of failure within a year by 30%. Drives with scan errors had up to a 50% failure rate. And in real-world use, we’ve seen that once those numbers start creeping up, they often accelerate fast.

Another flag to watch for is Reported Uncorrectable Errors. This means the drive ran out of ways to fix a bad block, even with spare sectors. If this number is greater than zero, it’s a strong sign the drive is wearing out.

But What Do Those Values Actually Mean?

S.M.A.R.T. uses values, thresholds, and raw numbers. It works like this:

• Value – ranges from 1 to 253. Higher is better.
• Threshold – the failure limit. If the Value drops below this, the drive is considered unhealthy.
• Raw value –  this is usually the actual count (e.g. number of reallocated sectors), but manufacturers sometimes “code” it in a way only they can decode. So don’t rely on raw numbers alone.

Should You Keep Using the Drive?

If all values are in the green, no reallocated sectors, and no uncorrectable errors, it’s probably okay for casual use. But if any health-related values are dropping (or if you’ve seen growing numbers across a few boots) it’s a sign to stop trusting that drive for anything critical.

If you want a second opinion on your drive’s health, take a screenshot of your S.M.A.R.T. results and post it in our community or show it to someone who works with hardware. We’ve helped users do that more times than we can count.

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