The message “not enough unallocated space on the target disk” may seem scary if you don’t know what unallocated space is.
You’ll receive this message mainly when trying to clone your OS to another hard disk or SSD.
Fortunately, this problem isn’t serious, and you can fix it with simple solutions.
Not Enough Unallocated Space On The Target Disk (Causes, Fixes)
1. Delete Free Space
Suppose you want to clone your entire operating system from your computer to your SSD.
Your SSD is partitioned and exactly the same size as your hard disk.
Everything should go fine as both of them are the same size, and you should be able to clone your OS with all its partitions to the SSD.
However, no matter how hard you try, you receive the message, “There’s not enough unallocated space on the target disk.”
That’s where the difference between free space and unallocated space comes into play.
Free space is partitioned, and most cloning software doesn’t write data on it to avoid data loss.
As mentioned earlier, free space and unallocated space are different.
Free space is a kind of partition that you have made but didn’t format.
That’s why it’s not usable by Windows.
On the other hand, unallocated space isn’t partitioned.
It’s dead space that’s not usable unless you change it into a partition and format it.
Thus, you need to turn all your disk space into unallocated space so that you can write data on it.
You can simply address the error by deleting the free space and turning it into unallocated space.
You can simply delete this partition via Disk Management.
Here’s how to do it:
Go to “Disk Management” by right-clicking the “Start” button.
When it loads up, select the partition you want to delete and right-click on it.
Select “Delete Volume.”
Click “Yes” to give Windows permission to delete all your data and remove the partition.
Now, you have enough unallocated space to expand your partition or do other jobs you wish.
2. Shrink Your Disks
If you can’t free up any space to create unallocated space, you can shrink one of your existing partitions.
This way, you remove some allocated space from your partitions and turn it into unallocated.
To do so, go to disk Management and right-click on the partition that you wish to shrink.
Choose “Shrink Volume” and enter the amount of new volume in the pop-up window.
Choose “Shrink” to start the process and click “Finish” when it’s complete.
3. Use The CHKDSK Command
The CHKDSK (the check disk utility) is a command that scans your entire hard drive and looks for problems to fix them.
Although it can take some time to fix your issues, this utility is effective and even helps prevent future problems.
It’s also recommended that you run this utility regularly to fix any potential problems that you’re not aware of.
However, remember to take a backup of your data every time you run this utility.
That’s because you may lose your data if the Check Disk utility runs into problems that it can’t fix.
To run the utility, press Windows + R keys together and type cmd to open the command prompt.
Type chkdsk H: /f /r /x in the command box, replace H with the letter of your unallocated hard disk and hit Enter.
This command contains all the parameters that you need to check for an unallocated drive.
If you want to check other parameters, you can refer to this guide by Microsoft.
Hopefully, this command will find all the potential problems with your hard drive and fix them for you.
4. Rescan Your Disks
When you try to create a new disk partition, you’ll receive a message warning that there’s not enough unallocated space.
That’s because Disk Management can’t identify the operation you’re trying to perform.
For example, you have expanded the volume, but Disk Management hasn’t detected it.
This problem applies to all configuration changes or updates in file systems, drive letters, or system volumes.
You’ll also receive this message when you try to extend a volume, but you don’t have enough space.
In such cases, reinstalling the operating system will help you solve the issue.
You may be able to get around it through other solutions, though.
One of them is rescanning the disks.
This is a simple solution that doesn’t take much time but makes the problem go away.
Here’s how to go about it:
Right-click on the “Start” button or press Windows key + X and select “Disk Management.”
When the Disk Management utility loads up, click on the “Action” tab in the menu bar and hit “Rescan Disks.”
Wait until the wizard completes the process.
Check if there are any problems with the disks.
It should be able to identify the changes to the drive and solve your problem.
5. Change Partition Size Using Third-Party Tools
When you try to extend volume size, you may have additional space in the Disk Management utility but receive an error message that you don’t have enough unallocated space.
If rescanning can’t solve your problem, you can try third-party tools to adjust disk size.
One of the best tools available is the EaseUs Partition Manager.
It allows you to clone, format, shrink, or extend your hard drive, in addition to moving your OS to SSD and many more.
It has a paid version and a free trial that you can use for all these purposes.
After downloading the app, launch it.
To make more space for your volume, you need to shrink another volume.
Right-click on the volume or partition you want to shrink and click on “Resize/Move.”
You can either drag the partition’s ends to match your desired size or enter the new size in the “Partition Size” box.
Now, move on to the volume you want to extend and choose “Resize/Move.”
Do the same by dragging the right toggle toward the unallocated space to extend the partition.
Hit “Execute 1 Operation” located on the top-right corner of the screen and select “Apply.”
6. Defragment The Disk
Fragmentation is a natural process that occurs in a hard disk over time.
When you store, delete, or resize data on your hard disk, it doesn’t do these actions in an organized way, storing things on the first free slot that it can find.
It may break a file into different pieces to make storage room for it.
That will lead to fragmentation, which could be one of the potential causes of the “not enough unallocated space” error.
The solution is simple: defragmentation.
Windows has a built-in defragmenter tool that can get the job done, and here’s how to use it:
Type “Disk defragmenter” in the Windows search bar and click on it in the search results.
Choose your disks one by one, click on the “Analyze disk” button, and check its fragmentation percentage.
If the percentage is over 10%, you need defragmentation.
Now, hit the “defragment disk” button to initialize the process.
You may need to type your admin password to continue the process.
Before delving into how you can address this error, it helps to know what unallocated space is, why you need it, and how it compares to free space.
What’s Unallocated Space?
When installing your operating system, you have to partition your hard drive and allocate some space to a few drive letters (like C, D, or E).
Now, for any reason, you may leave some space on the hard drive without assigning any partition to it.
Unallocated space on a disk drive or external storage is that unpartitioned space on these devices.
In other words, the unallocated space on the hard drive doesn’t belong to any drive letter or partition.
When space isn’t partitioned, it becomes unusable, which means you can’t store data on it or use other programs to write data on it.
Although unallocated space seems like dead space, you need it for several purposes, such as cloning a disk, a partition, or your whole operating system.
In this case, if you don’t have enough unallocated space for these purposes, you’ll receive the “not enough unallocated space” message.
What To Do With Unallocated Space
As mentioned earlier, having unallocated space isn’t necessary unless you want to clone a disk.
On the other hand, it doesn’t harm your system to have some unallocated space.
That said, you can allocate this extra space to new partitions to make new space for your drives and data.
When your hard drive has unallocated space, you can see in the file explorer that it’s smaller than its real size.
For example, if it’s 1TB, you’ll see it as 800GB. You could use this unallocated space in two ways:
1. Create A New Partition
You can change this dead space to usable space by making a new partition.
It’s easily doable through the “Disk Management” utility.
This way, you can fix the unallocated drive and create a new partition via “Disk Management.”
To do so, go to Disk Management by right-clicking the Start button.
After opening the Disk Management, right-click on the unallocated space on the hard drive.
Choose “New Simple Volume” and create a new partition.
Next, determine the “size of the volume” and choose a drive letter for it.
Pick your desired file system (FAT32 or NTFS).
Click “Next” and “Finish.”
2. Expand One Of The Existing Partitions
You can add this extra unallocated space to your existing volumes and increase your partition size.
Here’s how to do it:
After launching “Disk Management,” select the partition you want to expand.
Right-click on it and choose “Extend Volume.”
Now, you need to set the new volume size by adding a number equal to the size of the unallocated space to it.
Click “Next” and finish.
When Free Space Turns Into Unallocated Space
In some cases, the opposite of the above situations happens—your free and allocated space turns into unallocated space.
The space on a hard disk becomes unallocated in the following cases:
- The whole disk space becomes unallocated after you initialize a disk.
- After creating a partition on a hard disk, any space left unpartitioned will become unallocated.
- When you shrink or delete a partition, some portion of the space is left unused, which Windows will mark as unallocated.
- Virus attacks will make a storage drive marked as unallocated.
- You mishandle the hard drive, for example, eject it improperly.
- Power surges make disk partitions unavailable.
- File systems get corrupted or damaged or run into errors.
- Unexpected internal errors or bad sectors occur.
- The hard drive driver firmware is outdated.
While some of the above situations are quite normal during Windows operations, others need their own solutions.
Regardless of the reason for the unallocated hard drive, you can fix it by taking simple steps.
However, before fixing the problems, you should ensure you don’t have important data and files on the hard drive.
That’s because when you allocate space on the hard drive, you’ll format the drive, leading to permanent loss of your data.
Plus, when a partition or drive goes unallocated, you’ll lose all the data previously stored on it.
Recover Files From Unallocated Space On The Hard Drive
Recovering files from damaged or unallocated hard drives can be tricky.
Lots of third-party apps are available on the market, free and paid, to help you recover your data.
They’re all easy to use and have recovery wizards that take care of the whole process automatically.
To use EaseUs, go to this link and download the tool.
After launching the software, select the unallocated hard drive partition and click scan.
The wizard shows you the lost files through file names, extensions, or file types.
You can preview these files by double-clicking on them.
Select all the files that you want to recover and select “recover” to get them back.
Regardless of the tool you use for data recovery, always save your recovered files on another storage device such as an external hard drive.
AnyRecover is another safe tool that helps you retrieve lost data from unallocated drives, in addition to recovering data from recycle bin, formatted disk, and deleted files.
Data recovery on this tool is similar to EaseUs.
All you need to do is choose the drive you want to recover, press “Scan,” choose the files, and finally choose “Recover.”
Remo has the same straightforward process of data recovery.
Here again, the recovery wizard automatically restores your data without any complicated processes.
How To Fix An Unallocated Drive
Now that you’ve recovered all your vital data from your unallocated drive, you can fix it no matter what the reason was.
Here are the main solutions to this problem.
1. Run A Virus Or Malware Scan
As stated above, one of the main reasons that render a drive unallocated is a virus attack.
More often than not, running a virus scan and removing possible threats can solve your problem.
You could either use Windows Defender or another powerful third-party anti-virus to help you clean up viruses.
2. Update Your Hard Drive Firmware
As mentioned above, outdated hard drive software can cause the system to show free space as unallocated space.
Try updating the software to see if that fixes the issue.
You can head to the hard drive manufacturer’s website and search for the latest firmware update.
However, updating a hard drive firmware can be risky as any potential problem like a power outage can ruin the whole process and the whole drive.
So, if you’re not tech-savvy, you may want to leave this to a professional technician to make sure your hard drive remains safe.
3. Use The DiskPart Command
The DiskPart command is a powerful utility, similar to the Disk Management utility, which can empower you to fix problems with your drives and partition them better.
Hit Windows key + R, type in diskpart, and click “OK.”
Now, you should find all the available disk drives and the numbers assigned to them starting from 0.
Type “list disk” in the command window and press Enter.
Now, type Select volume C and replace C with the letter of the unallocated drive.
Now, type the following commands:
select volume C
delete volume override
This way, you can make your hard drive accessible without any errors regarding unallocated drives.
Now, you can create new drives by partitioning your hard drive.