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How to Merge C and D Drive in Windows 11/10 Without Losing Data - EaseUS

Updated by Roxanne on Aug 30, 2021

Q: Can I merge C and D drive in Windows 11/10 without losing data?

"I upgraded my computer from Windows 7 to Windows 11/10 and installed some new game software. As everything defaults to C, there are more and more data stored in C drive. Now I find that my system partition is nearly out of space while D drive has lots of free space. So, I want to merge C and D drive to enlarge the boot partition for better performance. 

But the Disk Management doesn't offer the option to merge C and D drive; if I insist on using Disk Management to do it, I have to delete D drive. I am wondering how I can merge C and D drive without losing data. Any suggestions?"

Many users have encountered the situation that C drive is running out of space. While facing such a problem, you can choose to merge C and D drive in Windows 11/10 to troubleshoot easily, especially when the D drive is nearly empty or has lots of free space. But how to merge C and D drive in Windows 11/10 without data loss? Read in-depth.

How to Merge C and D Drive in Windows 11/10 Without Losing Data

To merge C drive and D drive in Windows 11/10 computers, the simplest way is using a professional partition manager - EaseUS Partition Master, which enables you to merge partitions without data loss effortlessly. 

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In addition to merging partitions, EaseUS Partition Master provides more one-stop disk partition features, such as clone disk, create/delete/format partition, wipe data, disk/partition conversion, migrate OS to SSD without reinstalling, and so on.

Now, download EaseUS Partition Master and follow the steps below to merge C drive and D drive in Windows 11/10 without losing data. The screenshot shows how to merge E and F partitions. Merging C and D drive works the same way. 

Step 1: Select the target partition

Right-click on the partition which you want to add space to and keep, and select "Merge".

Run EaseUS partition manager software

Step 2: Select a neighbor partition to merge

Select one partition next to the former selected partition and click "OK" to continue.

Select partitions to merge

Step 3: Execute operation to merge partitions

1. Click the "Execute Operation" button at the top and then click "Apply".
2. The program will merge space and add files from the second partition to the first partition.

Select partitions to merge

See More: How to Extend C Drive Without Data Loss in 2 Ways 

Except for merging partitions, there are two ways to extend C drive without data loss by using EaseUS partition management software: one is resizing and moving drives, and the other is allocating space from D drive to C drive straightway.

1. Extend System Partition by Resizing Drives

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Option 1. Extend System C drive with unallocated space

  1. 1. Right-click on the System C: drive and select "Resize/Move".
  2. 2. Drag the system partition end into the unallocated space so to add it to the C: drive. And click "OK". 
  3. 3. Click "Execute Operation" and "Apply" to execute the operations and extend the C drive.

Option 2. Extend System C drive without unallocated space

  1. 1. Right-click a big partition with enough free space on the system disk, select "Allocate Space".
  2. 2. Select the system drive at the Allocate Space From (*) To section, and drag the end of System C drive into the unallocated space. Click "OK" to confirm.
  3. 3. Click "Execute Operation", it will list the pending operations, and click "Apply" to save the changes and extend the C drive.

0:00-0:32 Extend System Drive with Unallocated Space; 0:32-1:00 Extend System Drive without Unallocated Space.

2. Allocate Space from D to C to Increase C Drive

Here is the quickest and easiest way to extend C drive by moving space from other drives to the system drive without unallocated space. You can D, E, F, or any partition with free space to allocate space to the C drive.

Step 1. Right-click on the D: partition with enough free space and select "Allocate Space".

Select partition to allocate space

Step 2. Select the target partition - C: drive and drag the partition panel rightward to add the free space from D: drive to C: drive. Then click "OK" to confirm.

Allocate space to extend partition

Step 3. Click the "Execute Operation" button and click "Apply" to start the process of moving free space from D: drive to C: drive.

finish extending partition

To Sum Up

This post shows you how to merge C and D drive in Windows 11/10 without losing data by applying one of the world-renowned partition managers - EaseUS Partition Master. With this tool, you can effectively merge partitions in Windows 11/10/8/7.

What's more, we also introduce two ways to extend C drive without deleting or formatting using EaseUS disk management software, which can help you organize your hard drive and empty disk space to enhance operating system performance. 

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More FAQs About How to Merge C and D Drive

Now, let's check more hot topics about how to merge C and D drive in Windows 11/10 without losing data.

Is it safe to merge C and D drive?

Yes, you can safely merge C and D drive without losing any data with a reliable disk management tool, like EaseUS Partition Master. This partition master enables you to merge partitions in Windows 11/10 without deleting any partition.

How do I merge C and D drive in Windows 11/10 without losing data?

How do I combine C and D drives? You can make it with only three steps:

Step 1. Install and launch EaseUS Partition Master. Right-click on the C drive and select Merge.

Step 2. Select D drive next and click OK to continue.

Step 3. Click the Execute Operation button at the top and then click Apply to start to merge C and D drive without losing data. 

How can I use D drive when C drive is full?

When C drive is running out of space, you have three ways to use D drive space to extend C drive if D drive is to the right of the C drive in the graphical layout:

1. Delete D drive and extend C drive with the unallocated space via applying Disk Management or third party partition assistant.

2. Shrink D drive and use EaseUS partition manager to increase C drive with unallocated space.

3. Directly move the free space from D drive to C drive with EaseUS partition manager even there is no unallocated space.

How do you increase D drive space from C drive in Windows 11/10?

You can use the Allocate Space function of EaseUS Partition Master to easily move space from C drive to D drive to increase D drive space.

Step 1. Free Download and Install EaseUS Partition Master. Right-click C drive and select Allocate Space.

Step 2. Select the D drive as target partition. Drag the partition panel rightward to add space allocated from the source partition to the target one. Then click OK to confirm.

Step 3. Click the Execute Operation button and click Apply to start to increase D drive space from C drive.

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Updated by Roxanne

Roxanne is one of the main contributors to EaseUS and has created multiple posts on digital devices like PCs, Mobile phones, tablets, Mac, etc. She loves to share ideas with people of the same interest.

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