Merge 2 Unallocated Spaces & Add Unallocated Space to C (Full Guide)

Quick Answer

You can merge unallocated space into a partition via Disk Management if the unallocated space is directly adjacent to the partition on the same disk. If the unallocated space is separated by another partition, use MiniTool Partition Wizard to merge.

If unallocated space is divided into two by a partition, MiniTool Partition Wizard can merge the 2 unallocated spaces into one by moving the blocking partition.

How to Merge Unallocated Space to C Drive

Want to merge unallocated space to a partition? You can use Disk Management and MiniTool Partition Wizard. These two methods are suitable for different application scenarios.

Method 1. Use Disk Management

Disk Management is a Windows built-in tool. You can use it to shrink or extend a volume. The extend feature allows you to add unallocated space to a partition. Here is how to add unallocated space to C drive using this tool.

Step 1: Press Win + X and then select Disk Management to open it. Right-click the partition before the unallocated space and choose Extend Volume.

Step 2: Follow the wizard to add the unallocated space to the partition. You can keep the default options.

Method 2. Use MiniTool Partition Wizard

MiniTool Partition Wizard is a free partition manager that can help you extend and move/resize a partition easily. Here is how to merge unallocated space to the C drive using this software:

MiniTool Partition Wizard FreeClick to Download100%Clean & Safe

Step 1: Launch MiniTool Partition Wizard. Select the partition (C: drive, for example) you want to expand in the right panel. Then, click Extend Partition from the left action pane.

Step 2: Expand the “Take Free Space From” menu and select an unallocated space. Then, drag the sliding handle to decide how much free space to take. After that, click OK.

Step 3: Preview the partition expansion effect in the right panel. Then, click Apply to save the changes.

How to Combine Two Unallocated Spaces into One

An unallocated space may be divided into 2 unallocated spaces by a special partition like the EFI, System Reserved, Recovery, etc. In this case, you can use MiniTool Partition Wizard to move the partition’s location to merge the two unallocated spaces into one. Here is the guide:

Step 1: In MiniTool Partition Wizard, click the special partition located between 2 unallocated spaces. Then, select Move/Resize Partition from the left action panel.

Step 2: In the pop-up window, move the entire partition to the left or right to merge the 2 unallocated spaces. Then, click OK.

Step 3: Preview the combination effect and click Apply.

2 Free Tools to Merge C and D Drive in Windows 11/10

This post shows how to merge C and D drives without data loss using Disk Management and MiniTool Partition Wizard, respectively.

Read More

Why Can’t I Merge Unallocated Space Windows 10/11?

If you followed the above merge conditions and methods, but the merge still failed, the reason may be MSR partition blocking or the 2TB disk limit.

MSR Partition Is in the Way (GPT Disks)

On GPT disks, there is an MSR (Microsoft Reserved Partition), but it is not showing in Disk Management, which usually result in the following 2 issues:

• The unallocated space is immediately adjacent to the right side of the partition you want to extend, yet Extend Volume greyed out still.
• The unallocated space on a GPT disk is separated into two by an unknown entity.

The root cause is that the MSR partition is blocking the way, and you are unaware of it.

To solve the issue, you can use DiskPart to find it and then delete it. Here is the guide:

1. Press Win+ R, type “diskpart”, and press Enter to open it.
2. Type “list disk” and press Enter.
3. Type “select disk *” and press Enter. * is the number of the issue disk.
4. Type “list partition” and press Enter. Check the location of the Reserved partition to see if it is in the way. If so, proceed to execute the commands to delete it.
5. Type “select partition #” and press Enter. # is the number of the Reserved partition.
6. Type “delete partition override” and press Enter.

If you want to get back the MSR partition later, you can create it manually using this DiskPart command: Create Partition MSR (Size=*) (Offset=*).

The 2TB Disk Limit (MBR Disks)

If you initialize a disk larger than 2 TB to the MBR format, the portion exceeding 2 TB will be unusable. In other words, this space cannot be added to any partition or combined with other existing unallocated space.

To solve the issue, you can back up data, delete all partitions on the disk, and then re-initialize the disk to a GPT disk (right-click it in Disk Management and choose Convert to GPT Disk). Of course, you can also use MiniTool Partition Wizard to convert the MBR disk to GPT without data loss.

This article shows you 2 methods to merge unallocated space to a drive. It also tells you why the unallocated space fails to merge and is divided. Click to Tweet

Merge Unallocated Space FAQ

Bottom Line

This post shows you how to merge unallocated space to a partition easily using Disk Management and MiniTool Partition Wizard. You can pick one according to your condition.

In addition, unallocated space may be blocked by a special partition, preventing you from merging it with other partitions. This post also offers the solutions.

If you have any questions or suggestions while using MiniTool Partition Wizard, you can contact us via [email protected] to get a quick reply.