Normally, all your hard drives, internal and external, are listed under “This PC”, where you can open each drive and access your files.
If your hard drive is still not recognized, the fault may be physical and every new attempt counts. Before trying again, see how hard drive recovery works, starting with a free diagnosis.
Occasionally, however, a hard drive shows up as unallocated, and you can no longer store or open any files on it.
Sometimes, unallocated space appears on the hard drive you use every day. It may be a single partition or even the entire drive. In this case, the biggest risk is data loss, because the operating system can no longer access that space.
But don’t worry: in many cases, this problem can be solved!
In this article, we explain what an unallocated hard drive is, what can cause the problem, how to fix it and what to do to recover the data on the drive.
What does an unallocated hard drive mean?
Unallocated space is space on a hard drive that does not belong to any partition, so Windows cannot assign it a drive letter or use it to store files.
A brand-new hard drive is usually entirely unallocated: before you can use it, you have to create a partition, format it with a file system and assign it a drive letter, which also happens when you install an operating system.
In some cases, the drive you already use also has some unallocated space. This means that part of the disk does not belong to any partition and no data can be written to it.
To use this space, you need to create a new partition in it or extend an existing partition.
But in some (rare) cases, an entire hard drive becomes unallocated!
Yes: sometimes a hard drive that was working perfectly suddenly shows up as unallocated, making all the files and folders stored on it inaccessible. Usually the partition table has been damaged, but the data is often still on the disk.
Why does a hard drive become unallocated?
It’s normal for new hard drives to show up as unallocated. But if a drive you already use, with important data on it, shows this error, it may be due to one of the following causes:
- An unexpected error while writing data;
- Removing the drive without safely ejecting it;
- Malware and virus attacks;
- Partitions created or modified incorrectly;
- Problems with the hard drive’s driver.
Is it possible to recover files from an unallocated hard disk?
Yes, it often is, but be warned: it’s a delicate process to do on your own.
Searching the internet, you’ll find several tools, free and paid, that promise to fix this problem, but they require familiarity with technical procedures, and a wrong step can overwrite the data you want to recover.
So, instead of trying to recover files from an unallocated hard drive with these programs, leave it to a professional data recovery service.
That way, your data is handled safely, with the lowest risk of causing further damage to your hard drive.
How do I fix an unallocated hard drive?
Below are 3 simple steps to make an unallocated hard drive usable again. Important: these steps create a new, empty partition and format it, so only follow them on a new drive or one with no data you need. If the drive had files, recover them first.
Step 1: Create a new simple volume
The Disk Management tool lets you manage your computer’s hard drives as well as external drives.
With it, you can create a new volume in the unallocated space:
- Right-click the Start button and select Disk Management;
- Right-click the unallocated space and click New Simple Volume;
- When the New Simple Volume Wizard opens, click Next;
- Specify a size for the new partition and click Next;
- Choose a drive letter, set a volume label and leave the other options at their defaults. Click Next;
- On the final screen, click Finish.
Once you finish, the new volume will appear in Disk Management, and you’ll also be able to access it in File Explorer.
Step 2: Assign or change the drive letter
If the volume doesn’t have a letter, or you want to change it:
- Right-click the volume and select Change Drive Letter and Paths;
- Click Change to modify the existing letter, or Add if it doesn’t have one;
- Select the letter you want and click OK.
Step 3: Formatting
The New Simple Volume Wizard already formats the volume. You only need to format it again if you want to change the file system. Remember that formatting erases everything on the volume.
To do so:
- Open File Explorer and right-click the drive you want to format. Select Format;
- In the window that opens, choose the file system (such as NTFS or exFAT) and the allocation unit size;
- Click Start and confirm that you want to format the drive.
You can also format the volume in Disk Management:
- Right-click the Start button and select Disk Management (or go to Computer Management > Disk Management);
- Right-click the volume and select Format, then follow the steps in the window that opens.
How to recover data from an unallocated hard drive
The safest and most reliable way to recover data from unallocated space on your hard drive is to use a specialized professional service, like the one we provide at Bot.
Our experts are highly trained to recover your data without causing further damage to the hard drive.
When there is also physical damage, our professionals work on your hard drive in a Class 100 (ISO 5) cleanroom, an environment where airborne dust is strictly controlled to protect the drive’s internal components.
Furthermore, we collect your device free of charge (islands not included).
We’ll also analyze your hard drive, even if it has already been opened, and the standard diagnosis is free and ready within 48 hours.
We offer 24/7 support: if you have any questions about the data recovery process, just get in touch with us on Instagram or X (Twitter).
Read next
Conclusion
An unallocated hard drive, or unallocated space, is space on the disk that doesn’t belong to any partition, so it has no drive letter and can’t store files.
To make it usable, you can create a new volume, assign it a drive letter and, if needed, format it — which erases any data still in that space.
Common causes of an unallocated hard drive include errors while writing data, removing the drive without ejecting it, viruses and malware, partitions created or modified incorrectly and problems with the hard drive’s driver.
But whatever the cause, if the drive held important files, the first and most important step is to recover the data.
Only then should you apply the methods above to fix the unallocated hard drive safely.
For that, rely on a professional data recovery service, like the one we offer at Bot.
Start your data recovery with us and get a free diagnosis within 48 hours!
