Merging partitions refers to merge two partitions into one partition or combine a partition with unallocated space on hard drive to expand the space of a partition.
For example, if your hard drive is not partitioned reasonably and C drive is getting full but Partition D has enough free space, you can merge C drive and D drive to solve this issue. Moreover, if there are too many partitions on hard drive, it is inconvenient to manage them; if you store different data on so many different partitions, when you want to open one of them; you may forget where the data are saved. So combing two partitions can help reduce the partition number.
Free Merge partitions with Windows Disk Management
Windows 10/11 Disk Management can help you merge partitions, but you can’t merge two partitions with the tool directly; you must delete the partition at first and then use Extend Volume in Disk Management.
1. Open Disk Management. (You can type "diskmgmt.msc" in the Run window, or right-click on This PC and then select Manage >Computer Management > Storage > Disk Management.)
2. Locate the two partitions you want to merge and then delete one partition. For example, to combine C: drive and D: drive, you have to delete D: drive. Right-click on D: partition and select "Delete Volume".
PS.: Be aware that all data stored on D: drive will be lost. You'd better create a backup before doing it.
3. Next, right-click on the system partition and select the "Extend Volume" option.
4. Follow the Extend Volume wizard and accept the default options to merge two partitions in Windows 10.
As you can see, this function is only available when the unallocated space is adjacent to the partition you want to operate. You are not allowed to combine two partitions directly or merge partition with a non-contiguous unallocated space.
How to merge two partitions in Windows 10/11 without data loss
If you want to merge two drives or merge drive with unallocated space without data loss, you can employ a free partition manager – AOMEI Partition Assistant Standard. It supports adding non-adjacent unallocated space into one partition or combining two partitions easily and effectively without losing data. Free download it and check out the following guide about how to merge partitions in Windows 10 or Windows 11 without data loss.
1. Install and run it. Right click the partition you need to merge (e.g. Partition D) and choose Merge Partitions.
2. Choose the partition that you need to be merged (eg. Partition E) and click OK.
3. In the main interface, after confirming operation, click Apply and Proceed to commit it.
Only 2 partitions can be merged at one time, and the two partitions must be adjacent, but merge two or more parts of unallocated space into a partition is available and no matter the unallocated is next to the partition you want to merge or not.
You can merge data partition into system boot drive, but you cannot merge system boot drive into data partition.
Now, surely you have realized how to merge partitions in Windows 10/11. If there is an adjacent unallocated space behind the partition you want to extend. You can combine the partition with the unallocated space within Disk Management. If there is no such unallocated space and you want to merge two partitions like C drive and D drive without data loss, it is recommended to apply AOMEI Partition Assistant Standard.
Apart from merging two drives, AOMEI Partition Assistant Standard can help you to make bootable media, migrate OS to SSD and so on. If you want to experience more advanced functions like converting dynamic disk into basic, recover lost partition, moving applications from one drive to another drive, and converting system MBR disk into GPT, you can upgrade it to Professional version.