The disk space on your drive can become unallocated due to a plethora of reasons. If you find yourself in such a situation, there’s no need to panic, because it’s completely possible to recover data from an unallocated drive. What’s more, it may be easier than you think. Read our guide below to learn about what is unallocated space, how to recover data from it, and how to re-allocate the space.

What Is Unallocated Space?

In simple words, unallocated space is the space that Windows cannot use to store data. This unallocated space cannot be used to write any data by the programs on your PC. In most cases, allocation is done at the time of OS installation.

Unallocated space is different from free space. Windows and other programs installed on your computer can write data to free space, as it is already allocated and usable. In order to enable Windows to write files to unallocated space, you will have to allocate the space–either by creating a new partition, or expanding an existing one.

The unallocated space on your drive is not visible in Windows Explorer. To view the amount of unallocated space on your disk, Windows users can use the Disk Management utility. However, you still cannot any files or traces that may be available in this space. To recover data from an unallocated drive, you need specialized data recovery software.

Unallocated Disk Recovery Navigation

There are several common scenarios that result in unallocated space. It may range from user errors like accidentally deleting a partition or uncontrollable factors such as sudden power outages.

To make your life easier, here is a table that lists a few common scenarios and the solution for each one:
CasesSolutions
I forgot to allocate space when I installed Windows.Use Disk Management to allocate the space–either expand an existing partition or create a new one.
I need to allocate disk space after Windows Update.Again, you can use Disk Management to shrink a volume and allocate the space to another partition, or use the Diskpart command line utility to do the same.
I accidentally deleted the partition.Use data recovery software to perform unallocated partition recovery easily and safely. Subsequently, you can allocate the space.
I’ve unplugged my drive improperly.Check Windows Backup & Restore for an existing backup. If not available, use Disk Drill to perform unallocated disk recovery.
Unexpected Power Outage.Here too, it’s wise to check if Windows has an existing backup, then use data recovery software to recover the unallocated partition, and lastly, fix the unallocated hard drive using Diskpart or Disk Management.
Hard Drive malfunction.If the hard drive is physically malfunctioning, it’s best to contact a data recovery service. In case of logical errors, you can still scan the drive or partition using Disk Drill if it shows up in its interface.
Virus or Malware infection.Retrieve unallocated data using Disk Drill. After this, scan the drive for any malware using Windows Defender or any other antivirus program.
From the table above, it’s clear that data recovery software is the only way to recover data from an unallocated partition on Windows. It’s recommended that you perform the data recovery as soon as you discover the data loss. Another essential tip, is to first recover data from the unpartitioned space and then allocate it to some other partition.

How to Recover Data From Unallocated Hard Drive

Users looking to perform unallocated disk recovery have three options available to them–recover data from the unallocated drive using a third-party data recovery program, check if Windows has a backup of your data, or contact a professional data recovery service.

Let’s take a look at all three options in more detail:

Option #1: Recover Files from Unallocated Space Using Recovery Software

The easiest way for most users to recover their files from unallocated space on their disk, is to use a data recovery program. But, it’s essential to use only the best data recovery apps, because most programs are paid and the first data recovery attempt is usually the most successful.

In our data recovery demonstration, we’ll use Disk Drill Data Recovery, as it is one of the market leaders in data recovery, and for good reason. It has an easy to navigate interface that hides behind it an advanced data recovery algorithm that is effective, fast, and most importantly, fully supports data recovery from RAW partitions. Disk Drill’s scan not only searches for deleted files, but also the existing ones on your unallocated partition.

Here is how you perform unallocated drive recovery using Disk Drill:

  1. Download Disk Drill and install the program.
  2. Open Disk Drill, and select the unallocated partition. It will simply show up as “Unallocated” on Disk Drill’s home screen. Click on Search for lost data and Disk Drill will begin scanning the unallocated space.Disk Drill's home screen.
  3. Click on Review found items to see the recoverable files. Ideally, you should wait for the scan to be over, but you can view these files in real time as well.Review found items screen in Disk Drill.
  4. Now, select the files you want to recover using the checkbox next to each one. You can filter the files by file type, size, and more. Double-click on a file if you want to preview it. Once you’re sure, click Recover.List of recoverable files in Disk Drill.
  5. Select a recovery destination for the files. We recommend saving them on a different storage drive. Click on OK.File recovery destination selection screen.
  6. Disk Drill will recover the selected files.Data recovery complete screen in Disk Drill.

Option #2: Check Your System for Existing Backup

If you’d enabled Windows backup feature, called File History, you can get back your files if they were backed up.

It’s quite easy to perform unallocated drive recovery using File History:

  1. Connect the storage device you used to set up File History.
  2. Type “file history” in Windows Search (Windows Key + S).
  3. Select the Restore your files with File History option.File History option in Windows Search.
  4. Here, cycle through the backup you want to restore. Select the files using the checkbox, then click on the green Recover button.Windows File History recovery screen.
  5. File History will restore the selected file to its original location.

It’s always a good habit to create regular backups, and Windows File History can automate this process for you.

Option #3: Contact a Data Recovery Service

If the space became unpartitioned due to physical damage or severe logical damage, it’s best to contact a professional data recovery service, instead of attempting DIY unallocated drive recovery.

There are plenty of good data recovery services that can retrieve your data for you. Keep in mind that these are substantially more expensive than data recovery programs.

Typically, this is how data recovery services function:

  1. ☎️ You contact a data recovery service and explain your data recovery scenario.
  2. 🚚 The drive needs to be shipped or dropped off at the data recovery center.
  3. 💵 The company evaluates the drive and informs you how much data is recoverable, as well as the cost. The evaluation itself is free.
  4. ✅ You can decide whether you want to move forward with the recovery process.

How to Fix Unallocated Partition

After you’re done recovering your data, you can proceed to fix the unallocated hard drive and allocate the space to another partition, or create a new one. There are two ways to go about this–using Windows Disk Management or using the Diskpart command line utility.

If you’re unfamiliar with Windows Command Prompt, we recommend you use Disk Management.

Option #1: Reconfigure Partition Using CMD (Diskpart)

  1. Type cmd in Windows Search (Windows Key + S), right-click on Command Prompt > Run as Administrator.Windows Command Prompt in Windows Search.
  2. In the Command Prompt console, type diskpart and press Enter.The diskpart command in Command Prompt.
  3. After this, type list disk and hit Enter. The number under the Free column is the amount of unallocated space on your drive.The list disk command in Command Prompt.
  4. Type select disk x (replacing x with the disk number of the disk that has unallocated space–0 in our case) and press Enter.The select disk command in Command Prompt.
  5. Enter create partition primary size=x (replace x with the number listed under the Free column in the 3rd step). This is the size of the new partition that will be created. Press the Enter key.The create partition command in Command Prompt.
  6. Now, type list partition and press the Enter key.The list partition command in Command Prompt.
  7. On the next screen, type select partition x. Replace x the number of the newly created partition. Use the number listed under Size to find the partition easily, as it’ll be the same number you entered in step 5. Press Enter.The select partition command in Command Prompt.
  8. You now need to format the partition. To do so, type format fs=ntfs quick and press Enter. Wait for Diskpart to format the partition.The format command in Command Prompt.
  9. Lastly, you need to type assign and press Enter. If you have an older HDD, type active and press Enter after executing the assign command. If Diskpart displays an error after you type active, it simply means the command is not required.The assign command in Command Prompt.

Option #2: Recreate Partition Using Unallocated Space in Disk Management

  1. Press Windows Key + R to launch the Run application. Type diskmgmt.msc in the text box and hit Enter. This will open Disk Management.
  2. In the Disk Management window, look for the Unallocated section, as shown in the image below.Disk Management home screen with the unallocated section highlighted.
  3. Right-click on Unallocated and choose New Simple Volume.New simple volume option in Disk Management.
  4. Click Next on the New Simple Volume wizard welcome screen.Create simple volume wizard welcome screen.
  5. On the next screen, specify a size for the new partition and click Next.Partition size option in the simple volume wizard.
  6. Assign a drive letter to your drive using the drop-down menu, then click Next.Drive letter screen in the simple volume wizard.
  7. If required, modify the format options on the next screen. You can leave them as default and simply click the Next option.Format options in the simple volume wizard.
  8. Click on Finish. Disk Management will create the new partition.Finish screen in the simple volume wizard.

FAQ

Conclusion

Recovering data from an unallocated drive has been made easy because of data recovery software. Here are some pointers to keep in mind for successful unallocated disk recovery:

  • Attempt data recovery as quickly as possible and don’t write new files to the drive.
  • First recover the data from the unallocated space, then assign it to another partition.
  • Closely follow all the steps in the sections above. Especially, in case of Diskpart, since the command doesn’t ask for confirmation of any sort.