How to Merge Partitions in Windows 10 and 11 (Disk Management)

Merging partitions in Windows combines two sections of the same drive into one larger volume, for example folding an empty D: partition back into C:. Windows 10 and Windows 11 can do this with the built-in Disk Management tool, but only in one specific way: you delete the partition you don’t need and extend the neighboring one into the free space. This guide walks through it safely, explains the “Extend Volume grayed out” problem, and covers the command-line option.

Quick Answer

Back up the data on the partition you’ll remove. In Disk Management, right-click that partition and choose Delete Volume. Then right-click the partition directly to its left (such as C:) and choose Extend Volume, and accept the default size to use all the unallocated space.

Before You Start

• Back up everything on the partition you’ll delete. Deleting a volume erases its contents.
• The two partitions must be on the same physical disk and next to each other, with the unallocated space immediately to the right of the partition you extend.
• Don’t delete EFI, Recovery or MSR partitions; Windows needs them.
• If the drive uses BitLocker, make sure you have your recovery key.

Step 1: Open Disk Management

Right-click Start and choose Disk Management, or press Windows + R, type diskmgmt.msc and press Enter.

Step 2: Move Your Files Off the Second Partition

Copy everything from the partition you’ll remove (for example D:) to the partition you’ll keep, an external drive or cloud storage. Check that the copy is complete.

Step 3: Delete the Second Partition

1. In the bottom pane, right-click the partition to remove (D:).
2. Choose Delete Volume and click Yes.
3. The space now shows as Unallocated (black bar).

Step 4: Extend the Remaining Partition

1. Right-click the partition to the left of the unallocated space (C:).
2. Choose Extend Volume.
3. In the wizard, click Next, keep the maximum amount selected and click Next > Finish.

The partition grows immediately without a restart, and your files on it stay untouched.

Extend Volume Grayed Out?

• The unallocated space isn’t directly to the right. Disk Management can only extend into adjacent space on the right. A Recovery partition often sits between C: and the free space. Third-party partition tools can move partitions; Microsoft also documents manual steps for relocating the Recovery partition.
• The space is on another disk. Partitions on different physical drives can’t be merged with Extend Volume.
• The file system isn’t NTFS. Extend works on NTFS (and ReFS) volumes, not FAT32 or exFAT.
• It’s an extended/logical partition on an MBR disk and the space is primary (or vice versa).

Using DiskPart (Advanced)

Open Command Prompt as administrator and run diskpart, then:

list volume
select volume 3      (the volume to delete - double-check the number)
delete volume
select volume 2      (the volume to extend)
extend

DiskPart acts immediately and has no undo. Use it only if you’re comfortable, and verify volume numbers carefully.

Third-Party Partition Tools

Free and paid partition managers can merge non-adjacent partitions, move the Recovery partition, or merge without deleting data first. Download them only from the developer’s official website, back up first, and avoid bundled extra software during installation.

Frequently Asked Questions

Can I merge partitions without losing data?

With Disk Management, the partition you delete loses its data, so move files first. Some third-party tools merge while preserving data, but a backup is still essential.

Can I merge C: and D: if D: is to the left of C:?

Not with Disk Management. It can only extend a volume into space on its right.

Is it the same on Windows 11?

Yes. Disk Management works the same in Windows 10 and 11. Windows 10 reached end of support on October 14, 2025.

Summary

1. Back up the partition you’ll remove.
2. Delete it in Disk Management.
3. Right-click the partition on its left and choose Extend Volume.
4. Use a partition tool if the space isn’t adjacent.