By AOMEI / Last Updated February 26, 2020

▶ Q: Can I merge C drive with D drive in Windows Server?

“I have a problem that my system partition that with Windows Server 2012 installed is too small to install more software, while the D drive has a lot of free space that can be used to

merge these two partitions together to increase the capacity of C drive?”

▶ A: Merge C drive and D drive in Windows Server via two methods

Method 1: Merge C drive with D drive via Disk Management

Because Windows disk management does not support to merge partition C with partition D directly, the only solution to this issue is that you have to delete partition D, making it an unallocated space, and then you can merge this unallocated space into C drive.

Warning: To delete partition D means you will lose all your data in it unless you make a backup or move the data to another location.

Step 1. Press Windows + R simultaneously, input diskmgmt.msc and click OK.

Step 2. Right-click D drive, choose Delete Volume and click Yes to confirm.

Delete D Partition

Step 3. Right-click C drive and choose Extend Volume.

Step 4. Follow the prompts to complete the operation.

Method 2: Merge two partitions with AOMEI Partition Assistant Server [Without Data Loss]

To combine C drive with D drive without deleting partition, you can turn to a third-party partition manager software for Windows Server, AOMEI Partition Assistant Server. It is compatible with Windows Server 2019/2016/2012 (R2)/2008(R2)/2003 and Windows 10/8.1/8/7, XP and Vista. After merging, you can see an enlarged C drive and a folder named D drive, which contains all data saved in the previous D drive.

Note: To settle C drive full while D drive has plenty of space, you can also use the partition manager software’s Allocate Free Space to allocate free space from D drive to C drive rather than merge these two partitions.

Now, install and run AOMEI Partition Assistant Server on your machine and refer to steps on how it merges two partitions: C drive and D drive in Windows Server.

You can download its demo version to have a try!

Step 1. In the main interface, right-click C drive and choose Merge Partitions.

Merge Partition

Step 2. Tick the tick adjacent partitions (merge unallocated partition is not in this limit) you want to operate. Here choose partition C and D. Click OK to continue.

Step 3. Then a preview of this operation comes out. To make it into effect, click Apply and Proceed at the top-left corner.


  • Only two partitions can be combined at one time and these two partitions must be contiguous while you can merge two or more unallocated space into a partition no matter the unallocated space is contiguous the partition.

  • The host partition needs to have at least 1GB free space before merging.

  • You can merge data partition into system boot partition, but you cannot merge system boot drive into data partition.

  • You can also use AOMEI Partition Assistant Server to settle other issues, such as partition is deleted accidentally, basic disk is converted to dynamic mistakenly, etc.