Have you plugged in your external hard drive and seen the message “You need to format the disk in drive before you can use it”? It’s one of the most common drive issues out there. There’s always a post online from someone asking what to do next.
Well, that’s exactly what you’ll find below.
We’ve pulled together practical steps, reliable tools, and solid methods to help you figure out what’s going on and what to do next.
Let’s start with why Windows is even asking you to format the external drive in the first place.
This usually means your computer can’t read the file system on the external hard drive. It could be corrupted, missing, or using a format Windows doesn’t understand. That’s when it throws up the format prompt; Windows simply can’t make sense of what it’s seeing and offers to start fresh with a clean, empty external drive.
Here are some of the usual suspects:
Now, most people who search for answers to this problem do it for one reason: they’ve got important files on that drive. Photos, work stuff, maybe backups. And they know that if they click “Format,” those files are gone. That’s why it’s worth taking a smarter route first.
Here’s a basic checklist we’d suggest before doing anything else:
There are cases where the problem is caused by serious physical damage, but more often, it’s a logical issue. That means the data structure on the drive is damaged, not the hardware itself. And that’s something you can often fix yourself with the right tools.
But before we get into any of the fixes, let’s talk about your data first.
If your external hard drive is asking to format and you actually care about the files on it, start here.
Yes, there are some fixes that can make your drive usable again without losing anything. But nobody can guarantee that those fixes will work flawlessly. In fact, trying to “fix” the drive before data recovery could make things worse; just take a look at what sometimes happens with the CHKDSK utility. A failed repair attempt can overwrite file structures, damage partition data further, or make recovery way harder than it needs to be.
So here’s the safer move: recover your files first, then deal with the repair.
📝 By the way, if you already clicked “Format” and now your disk looks empty. This method still has a good chance to pull your data. A quick format doesn’t actually erase the files; it just clears the file system map. As long as new data hasn’t overwritten your old files, recovery software can still dig them out.
To retrieve your data, we’ll use our partner software, Disk Drill. It shows solid results across pretty much every file system you’ll run into: NTFS, exFAT, FAT32, HFS+, APFS, ext4, and more. Whether the drive was used on Windows, macOS, or even Linux, Disk Drill can usually recognize it and scan it.
On top of that, it’s easy to use and it includes a few extra features that come in handy when your drive is acting up. Let’s get started:
Now your data should be safe in a different location, separate from the problematic external drive. That’s already a huge win. You’re halfway there.
While you’re still in Disk Drill, it’s a good time to take advantage of another extra tool: S.M.A.R.T. monitoring. This feature lets you check the health status of your drive using built-in diagnostics from the hardware itself.
Find it under Extra Tools, click on S.M.A.R.T. Monitoring, and enable it. It might prompt you to install an additional driver; go ahead and do it. Once it's set up, you’ll see detailed info about your drive’s condition: temperature, bad sector count, spin-up time, and more.
If all you see is “Good” in green, great, your drive just has a minor logical issue. Something you can fix, and once it’s resolved, you’re done.
But if you see warnings in red or anything marked as failing, that means the drive is compromised. You can’t fully trust it with important data from this point forward. You might still be able to get it working again, but it’s no longer safe for anything critical. It’s best used for temporary storage or testing, not long-term backups.
Let’s go through the fixes that can help get your external hard drive back into usable shape without formatting it right away. Some of these are quick and easy, others a bit more technical. We’ll start with the simpler ones and work our way up.
Start with what’s built into Windows. If the problem is caused by minor file system corruption, these tools can sometimes fix it in a couple of clicks.
CHKDSK and Error Checking are basically the same tool: one’s the graphical version, the other is command-line. Both scan the drive for errors, try to fix broken file system structures, and can mark bad sectors so they’re no longer used.
If you’re not comfortable with command prompts, start with the Error Checking tool. It’s easy:
Windows will go over the file system and either fix small issues on its own or let you know nothing was found.
Alternatively, you can use CHKDSK directly through the command line or Windows Terminal:
This version gives you more control and a detailed view of what’s happening. The /f tells Windows to fix file system errors, and /r checks the entire surface of the disk for bad sectors.
These are simple fixes, and in some cases, they do work. But like we already mentioned, they’re not risk-free. Running a repair tool can lead to some data loss.
So before you try anything, make sure you’ve either backed up your data to your system drive like we showed earlier, or you’re okay with the possibility of losing a few files.
This option isn’t as simple as Error Checking or CHKDSK, but it’s a lot more powerful if you’re dealing with a RAW file system or a missing partition.
TestDisk is a free, open-source recovery tool that works at the partition level. It doesn’t have a modern user interface (it runs in a terminal window), but don’t let that throw you off; it’s used by many people for a reason. It can rebuild partition tables, recover lost partitions, and make some RAW drives readable again.
Again, like with CHKDSK, there’s always some risk involved when you’re trying to repair a drive. TestDisk is powerful, but it’s still making changes to low-level disk structures. If something goes wrong, you could make things worse or lose access to your data for good.
So if you haven’t already pulled your data, this is the time to do it.
Here’s how to get started:
After TestDisk completes the write process, exit the program. You may need to restart your computer for the drive to appear properly in File Explorer. Sometimes it shows up instantly, but not always.
If none of the methods worked for you, then your external hard drive needs to be formatted, there’s really only one thing left to do at that point.
And honestly, if you’ve already used a data recovery tool and got your files off safely, what’s really stopping you? You’ve already done the hard part. Formatting is a clean slate. It wipes whatever mess was confusing the system and sets the drive up fresh with a working file system.
📝 Note. Formatting won’t fix physical damage, but it often clears up logical problems once recovery’s done. So if you skipped our section on data recovery, go back and check it first (you’ll want to get your files off the drive before wiping anything). And while you’re at it, don’t forget to check the S.M.A.R.T. status like we showed earlier. It’ll give you a clearer picture of whether this external drive is still reliable or if it’s time to retire it.
We recommend doing a full format (not a quick format) through Disk Management:
That’s it. If the format completes without errors, your drive should be usable again.
Now, about that Quick Format checkbox, we recommend unchecking it for a reason: Quick and Full Format are very different.
Of course, there are cases where you might need to turn to a professional data recovery service; if your external drive is too far gone, that’s usually outside the scope of DIY.
But in our experience, 8 out of 10 cases are just good old logical issues, like file system corruption or lost partitions. These can often be fixed at home without any special hardware or deep technical knowledge. You don’t need to be a pro to safely recover your files or get your drive working again; you need the right tools, a bit of patience, and the willingness to follow a few steps.
There are also some rare cases where the drive refuses to be formatted, even if you go along with the prompt and try to format it through Windows. It just fails. In situations like that, a few users have had success with a third-party utility called HDD Low Level Format Tool. It performs a true low-level format (something Windows doesn't do), which can sometimes reset a stubborn drive that’s stuck in a weird state.
Just be aware: low-level formatting, like full formatting, wipes everything. There's no going back. That’s why we always recommend thinking about your data first, and fixes after. If you follow that simple rule, chances are you’ll avoid permanent loss and give yourself the best shot at recovery.