How to change partition size in Windows 10

by Andy, Updated on: March 1, 2021

This article introduces how to change partition size for Windows 10 computer without losing data. Resize disk partition with native Disk Management and partition editor software.

When system C drive is running out of space, nobody wants to start from scratch, so many people search by Google to find a better way. In technical forums, many people have similar questions such as:

• Is it possible to change partition size in Windows 10 without reinstalling OS.
• Is it safe to re-size partition and which tool is better to change allocated partition size.

The answer is definitely yes. To change volume size in Windows 10 laptop and desktop, there are 2 options: Windows built-in Disk Management and third party partition editor software. Because of many shortages, Disk Management is not the best tool to change partition size.

Change partition size with Windows 10 Disk Management

Windows 10 Disk Management inherited Shrink Volume and Extend Volume functions from previous version. Shrink Volume can decrease the size of both system C drive and data volumes. Extend Volume can increase size of a drive when there is adjacent Unallocated space. Both functions are safe to change partition size in Windows 10 (32 & 64 bit).

However, if you want to extend a volume by shrinking another one, Disk Management cannot help you, learn why.

How to decrease partition size in Windows 10:

1. Press Windows and X on the keyboard and select Disk Management from the list.
2. Right click the drive you want to decrease and select Shrink Volume.
3. Enter the amount of space (1024MB=1GB) and click Shrink to execute.

This drive will be shrunk within a short time in most cases.

Restrictions of Shrink Volume function:

1. Only NTFS partition can be shrank, FAT32 and other types of volumes are not supported.
2. Unallocated space can only be generated on the right side.
3. Sometimes you can only shrink little space because of some unmovable files are located, even though there is large amount of free space in this drive.

How to increase partition size in Windows 10:

Only when your disk drive configuration meet the requirements below, Extend Volume is workable to increase partition size.

1. There must be adjacent Unallocated space on the right side of the drive that you want to extend. If there’s no such Unallocated space, you must delete the right contiguous partition.
2. The drive that you want to extend must be formatted with NTFS, FAT32 and other types of partitions are not supported.
3. On MBR disk, the partitions to be deleted and extended must be the same Primary or Logical drive. Otherwise, you still cannot extend partition after deleting the right contiguous one.

To increase volume size with Disk Management:

1. Right click the NTFS partition that has right adjacent Unallocated space and select Extend Volume.
2. Simply click Next in the pop-up Extend Volume Wizard window.
3. Click Next to use default selected disk and space, or change manually.
4. Click Finish to execute.

Adjust partition size with partition editor

Comparing with Windows 10 Disk Management, NIUBI Partition Editor has advantages while resizing partition, for example:

• Both NTFS and FAT32 partitions are supported to shrink and extend.
• Unallocated space can be made on either left or right when shrinking a drive.
• Partitions can be extended via 1 step with adjacent Unallocated space on either side.
• Unallocated space can be moved and combined to any nonadjacent partition on the same disk.
• If there is not plenty of space in the same disk, NIUBI can copy to a larger one and extend partition with extra space.

How to change partition size in Windows 10 with NIUBI Partition Editor:

Download this program and you’ll see all disk partitions with structure and other information. In my test computer, there are drive C, D, E and system reserved partitions.

There are two options when decrease partition size, right click this partition (here is D:) and select «Resize/Move Volume».

Option 1: If you drag left border towards right in the pop-up window,

Then Unallocated space will be produced on the left side.

Option 2: If you drag right border towards left in the pop-up window,

Then Unallocated space will be produced on the right side.

These Unallocated space can be used to create new volume or combine to other partition.

To increase size of partition C:

Right click C and select «Resize/Move Volume» again, drag right border rightwards to combine Unallocated space.

To increase size of partition E:

Right click E and select «Resize/Move Volume» again, drag left border leftwards to combine Unallocated space.

If you want to decrease E to increase C, follow Option 1 to make Unallocated space on the left side of E. Before adding Unallocated space to C drive, there is an additional step to move Unallocated space to left side of D. To do this, right click drive D and select «Resize/Move Volume», drag middle position towards right in the pop-up window.

Take care of data while resizing disk partition

There is potential system and data damage risk while change partition size for Windows 10 computer. So you’d better back up first and use safe partitioning software. Better than other software, NIUBI Partition Editor provides powerful 1 Second Rollback, Virtual Mode and Cancel-at-well technologies to protect system and data.

Besides changing partition size, it helps you do many other operations such as: merge, convert, defrag, copy, hide, wipe and scan partition. Initialize, convert, set read-only attribute to disk, etc.

Freely and Easily Change Partition Size in Windows 10

You can easily change partition size in Windows 10 via Disk Management, Diskpart utility or a free and easy-to-use partition manger – AOMEI Partition Assistant Standard.

By AOMEI / Last Updated October 16, 2019

Why change partition size in Windows 10?

As times goes, you might be unsatisfied with the current size of the hard drive partition and want to resize partition in Windows 10 under different situations:

A partition like Partition C (system drive) is allocated with small capacity and it is almost running out of space. To avoid the possible follow-up issues, you may want to extend the partition.

A partition is too large. It is possible that there is only one partition on your large hard drive. To manage data better, it’s wise to shrink the partition and create new partition with the unallocated space.

Whatever the reasons, you can find out a proper way to resize your partition in Windows 10 in the following content.

How to resize partition in Windows 10 (3 ways)?

Pick up one method about changing hard drive partition size in Windows 10 based on the specific condition.

Change partition size within Disk Management

Disk Management is a built-in tool in Windows 10, which is able to shrink/extend/create/delete/format partition. With this tool, you should shrink partition to gain unallocated space or extend the partition with contiguous unallocated space.

1. Press Windows + R, input “diskmgmt.msc” and hit Enter key to open Disk Management.

2. In Disk Management, right click the partition that you want to extend or shrink.

3. In the pop-up menu, choose Extend Volume or Shrink Volume and follow the wizard to complete the operation.

Notices:

Extend Volume will be greyed out if there is no adjacent unallocated space behind the partition that you want to extend.

You might be unable to shrink C drive out of unmovable files, even when it has free space.

Resize partition via Diskpart

It is also available to increase or decrease partition capacity via Diskpart utility. Here are detailed steps:

1. Press Windows + R simultaneously, input “diskpart” and click OK.

2. Type” list disk” and hit Enter.

3. Input “select disk n” and press Enter key. (n is the number that holds the partition that you want to resize.)

4. Run “list partition” command.

5. Run “select partition m” command. (m refers to the number of the disk that you need to extend or shrink.

To extend the partition, input “extend size = x” and press Enter (x is the size in MB that you want to add to the partition).

To shrink partition in Windows 10, input “shrink desired=x” and hit Enter (y is the size in MB that you want to shrink the partition by).

Note: To extend partition, please ensure that there exists a contiguous unallocated space behind the partition that going to be extended; otherwise, you can’t extend the partition.

Change partition size via a free yet powerful tool

When it is not available to get an unallocated space behind the partition that you are going to extend, it is time to employ a trusted and full-featured partition manager – AOMEI Partition Assistant Standard, specially designed for Windows system. It can work under Windows 10/8.1/8/7, XP and Vista.

It allows you to extend partition with non-adjacent unallocated space without data loss via Merge Partitions function and enables you to shrink partition beyond its half size. Free download it and have a look at how it works.

Step 1. Install and run the software. Right click the partition (here is D drive)that you want to shrink and choose Resize Partition.

Step 2. In the pop-up window, drag leftward to shrink the partition. Then, click OK.

Step 3. Then, there will be an unallocated space on the hard drive. To extend C drive, right click it and choose Merge Partitions.

Step 4. Tick C drive and Unallocated. Then, click OK.

Step 5. Back to the main interface, click Apply and Proceed to execute operation.

PS.:

If the hard drive has unallocated space, you can skip Step 1 and Step 2.

You can upgrade AOMEI Partition Assistant Standard to Professional version and you can use more functions, such as allocating free space, quick partition, partition recovery, etc.

Conclusion

It’s easy to change partition size in Windows 10 and you can choose a proper way from what aforementioned. If your current hard disk is too small, it is not practical to fix partition full issue completely. You can choose to replace your current small disk with a larger one.

How to resize Windows 10 partition without losing data

by John, Updated on: March 1, 2021

This article introduces how to resize partition in Windows 10 (32 & 64 bit) without losing data or reinstalling OS/programs. Resize volume with Windows 10 Disk Management and free partition editor.

C drive out of space is common issue in Windows 10 computers, no matter you use desktop or laptop, SSD, mechanical disk or even RAID arrays. The fast way to solve this problem is resizing partitions to increase C drive free space, but to many computer users, it is not an easy task to resize Windows 10 partitions. In technical forums, many people ask similar questions such as: «is it possible to re-size disk partition without reinstalling OS, my c drive is full but there is plenty in D«, «Is it safe to resize my Windows 10 drives, will it cause data damage?«

In this article I’ll explain why disk partitions can be resized, and how to resize partition in Windows 10 with built-in Disk Management tool and free partition editor software.

Why disk partition can be re-sized?

A partition (also called as drive or volume) is just part of entire hard disk and there could be many partitions in a disk. Many people use partition C for Operating System, create separate partitions for programs and personal files. Before saving files to a partition, it must be formatted with a file system. The common file system in Windows computer is FAT32 and NTFS. Take MBR style disk as example:

1. Operating System read the parameters in MBR (master boot record) and then it knows how many partitions in this disk, and the start/end position of each partition.
2. From DBR of each partition, Operating System gets the list of all files in this partition including name, create date, type and many other parameters of each file.
3. From the parameters, Operating System can locate the data area.

To change a file, Operating System simply modify the data area and then update the associated parameters in DBR.

To resize partition in Windows 10 computer, it is much easier if it doesn’t require moving files of this partition. In this case, the partition tool just modify the parameters of start and end position of this volume. But if file moving is required, it is much more complicated, besides updating partition position, the partition tool also move location and update parameters of all file in this volume, so it cost much longer time if there are large amount of files.

Windows 10 partition resizing tools

There are two kinds of tools to resize volume in Windows 10: built-in Diskpart command or GUI Disk Management and 3rd-party partition manager software.

Some people like to use Windows native tools thinking they have best compatibility, but it’s not true. I’ve encountered the issue at least 3 times that Disk Management destroyed my drives when shrinking partition. Be careful when there are many partitions including Logical drive on a disk.

Third party software is much more powerful and it’s much easier to resize partition for Windows 10/8/7 computers. However, few partitioning software are safe enough. Therefore, before resizing partition, you’d better make a backup and run the safest program. Otherwise, your system and partitions may be damaged.

Better than other tools, NIUBI Partition Editor has unique 1 Second Rollback, Virtual Mode and Cancel-at-well technologies to protect system and data. In addition, it has Hot-Resize technology to help resize disk partition without rebooting and advanced file-moving algorithm to help resize partition 30% to 300% faster.

How to resize partition in Windows 10 using Disk Management:

Windows 10 Disk Management has no «resize volume» function, partition resizing is realized by Shrink Volume and Extend Volume. Note: only NTFS partition is supported. FAT32 and EFI partition can’t be resized by this native tool.

To shrink a volume:

1. Press Windows and X on keyboard and select Disk Management from the list.
2. Right click the partition and select Shrink Volume.
3. In the pop-up window, enter the amount of space and then click Shrink to execute.

To extend a volume:

1. Right click this drive in Disk Management and select Extend Volume.
2. Simply click Next in the pop-up Extend Volume Wizard window.
3. Confirm the operation and click Finish to proceed.

To extend partition in Windows 10 Disk Management, your disk partition layout must meet the requirements:

1. There must be adjacent Unallocated space on the right of this drive.
2. If there’s no such space, you must delete the right partition to get contiguous Unallocated space.
3. On MBR style disk, Free space deleted from Logical drive cannot be added to any Primary partition, even if it is right adjacent.

Windows 10 has another native tool — Diskpart to help change partition size. Diskpart is a command line tool, although it works in different way, it has same limitations with Disk Management. Learn how to extend partition with diskpart.

If you want to extend C drive by shrinking D or any other partition, it is impossible with Disk Management or diskpart command. Because, Shrink Volume can only shrink a partition (such as D:) towards left and make Unallocated space on the right side, but to extend C drive with either native tool, Unallocated space must be on the left side of D. This is the reason why Extend Volume is disabled for C drive after shrinking D.

As you see in the screenshot, Extend Volume is also disabled for E drive, because Unallocated space is on its left side.

Resize Window 10 volume with free partition software

To resize partition in Windows 10 without losing data, NIUBI Partition Editor is better choice. Both NTFS and FAT32 partition can be resized. Unallocated space can be generated on either left or right when shrinking partition. This space can be combined to any contiguous and non adjacent partitions on the same disk.

Download this program, you’ll see all storage devices with partitions structure and other information on the right, available operations to the selected disk or partition are listed on the left and by right clicking.

How to resize partition in Windows 10/8/7 laptop/desktop with NIUBI:

Right click a partition (here is D:) and select «Resize/Move Volume«, you have two options in the pop-up window.

Option 1: If you drag left border towards right in the pop-up window,

Then partition D is resized and 20GB Unallocated space is made on the left.

Option 2: If you drag right border towards left in the pop-up window,

Then Unallocated space will be made on the right side of D drive.

If you want to extend C drive partition, follow Option 1 above to make Unallocated space on the left side of D. Then right click C: drive and select «Resize/Move Volume» again, drag right border rightwards to combine this Unallocated space.

Then two pending operations are created on bottom left, you need to click Apply on top left to take effect.

If you want to extend partition E, follow Option 2 above to make Unallocated space on the right of D drive. Then right click E: and select «Resize/Move Volume» again, drag left border leftwards to combine the Unallocated space.

If you want to shrink E to extend non adjacent partition C, follow the steps below:

1. Shrink drive E: and make Unallocated space on the left side.
2. Move Unallocated space from right side of drive D: to the left.
3. Add Unallocated space to C drive.

To move Unallocated space from right to the left, right click drive D: and select «Resize/Move Volume», drag the middle towards right in the pop-up window:

Watch the video guide how to resize volume in Windows 10 (32/64 bit):

Besides resizing partition for Windows 10 laptop and desktop, it helps you move, merge, copy, convert, defrag, wipe, hide partition, scan bad sectors and much more. There’s free edition for Windows 10/8/7/Vista/XP home computer users. Except 1-Second Rollback technology and bootable media builder, it is the same with paid Professional edition.