Extend primary partition

How to resize/extend primary partition on Windows 10

When a hard drive is running low on disk space, you can extend it with free space in other drives of the same disk. However, whether it is possible or safe depends on the tool your are using. To resize and extend primary partition on Windows 10, the native Disk Management is an option, but not all partition drives can be resized due to some inherent limitations.

In this article, I’ll introduce how to resize primary partition in Windows 10 with both Disk Management and 3rd-party professional partitioning software.

Extend primary partition

What is Primary partition

  • Primary Partition is the hard disk partition where both Windows OS and other data can be stored, and it is the only partition that can be set Active attribute. The system reserved and other partitions that are created by Windows must be Primary, otherwise, you cannot boot Windows.
  • Logical Partition is the just part of the Extended partition and simulated as a drive. Like primary partition, a logical partition can be used to install Windows and save any other types of files, but it cannot be set as Active.

In a GPT style hard disk, you can create many partitions with an unique drive letter (C, D, E, etc.), in addition, all partitions can only be created as Primary partition.

The strategy to organize partition and files of MBR disk is different with GPT disk. There are only 4 entries in master boot record of MBR disk, from which Operating System knows the size and position of each partition.

  • You can only create 4 partitions, if they are created as Primary, then all of the 4 entries are assigned to these partitions.
  • If you want to create more than 4 partitions, one of the entries must be assigned to Extended Partition.
  • The same with Primary partition, Extended partition is a real disk partition but works like a container.
  • All Logical partitions must be created in the Extended partition and works like a simulated drive. However, you won’t feel any difference in daily usage.

MBR vs GPT disk

Limitation of Disk Management

As I said in the beginning, not all partitions can be extended in Windows 10 Disk Management, because there are some limitations. In a GPT disk, there 2 main limitations:

1. There must be adjacent Unallocated space

For example: when you shrinking drive D with Shrink Volume, Unallocated space can only be generated on the right side of D. But to extend C drive with Extend Volume, the Unallocated space must be on the left side of D. That is to say, you cannot extend primary partition C by shrinking the adjacent drive D, let alone other nonadjacent data drives.

Extend Volume greyed out

As you see in my Windows 10 laptop, Extend Volume is disabled for C drive after shrinking D.

2. Only supports NTFS partition

As we know, NTFS and FAT32 are the most common type of partitions in Windows computer, but the built-in Shrink and Extend Volume only support NTFS partition.

Cannot extend partition

To show you the limitation, I formatted drive D from NTFS to FAT32. As you see, Extend Volume is greyed out for D drive even though there is 20GB Unallocated space on the right side.

If you use MBR disk, there is an additional limitation:

3. Cannot extend Primary partition by deleting Logical drive

As I show you above, we cannot extend C drive by shrinking D, so some people try to delete D instead. Then the disk space of D will be converted to Unallocated, so Extend Volume is enabled for C drive. It works indeed in GPT disk, but in MBR disk, you cannot extend primary drive C if D is a Logical partition.

The hard disk of my Windows 10 laptop is formatted as GPT when installing, so I have to show you the limitation on my Windows 7 desktop.

Extend c drive disabled

As you see, the System Reserved and C drive are Primary, drive D, E and F are Logical in Extended partition. I cannot extend C drive by deleting D. Have you noticed the difference? Disk space of a Logical partition will be converted to Free instead of Unallocated after deleting.

Note: all programs and Windows services in drive D stop working after deleting, so it is not suggested.

Resize primary partition with software

It’s annoying right? But luckily, it is very easy to extend primary partition or any logical drive with professional partition software. Comparing with Disk Management, NIUBI Partition Editor has many advantages, for example:

  • Both NTFS and FAT32 partitions are supported to shrink and extend.
  • It’s easier by simply dragging and dropping on the disk map.
  • Unallocated space can be produced on either side when shrinking a partition.
  • If there is not plenty of free space is drive D, NIUBI can shrink any nonadjacent drive and move Unallocated space to behind C drive.

NIUBI Partition Editor

How to extend primary partition

Download and install NIUBI Partition Editor, right click drive D and select Resize/Move Volume.

NIUBI main window

Step 1: Drag left border rightwards in the pop-up window, or enter an amount behind “Unallocated space before” manually.

Shrink D drive

Click OK, drive D is shrank to 30GB and 20GB Unallocated space is generated on the left side of D.

Unallocated generated

Step 2: Right click C drive and select “Resize/Move Volume” again. In the pop-up window, drag the right border rightward to combine the 20GB Unallocated space.

Extend C drive

C drive is extended to 50GB, click Apply on top left to execute. The pending operations with  can be done in Windows without rebooting.

C drive extended

If you still do not understand how to resize primary partition on Windows 10, watch the video:

In Summary

Windows 10 Disk Management has the ability to change partition size with Shrink and Extend Volume functionalities, but because of the limitations, few partitions can be shrank and extended. To resize and extend primary partition on Windows 10, NIUBI Partition Editor is better choice. Equipped with unique 1 Second Rollback technology and file-moving algorithm, it is much safer and faster than other tools.

Download to try

How to resize and extend primary partition on Windows 10 safely?
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