EaseUS Partition Master

A simple partition tool to manage disk space in Windows 10

How to Extend System Partition in Windows 10

Updated by Gemma on Feb 01, 2021
Written by Brithny

Provided solutions for extending system C drive can also be applied to increase other partitions on your Windows 10/8/7/XP PCs.

Part 1. 3 Methods to Extend System Partition with Adjacent Unallocated Space

Part 2. Extend System Drive without Unallocated Space

Can I extend my C drive partition in Windows 10

When the C drive is out of space, many Windows users would come up with the need to extend the system C drive. Actually, extending system partition on your Windows 10 computer can benefit you.

By extending your system volume or C: partition, you can make full use of free or unallocated space that is not being used by other partitions. And the significant benefit of extending C drive is that your computer will gain better, optimized performance with faster speed. 

If you are having the question of "Can I extend my C drive partition in Windows 10", the answer is yes. Powerful partition manager software - EaseUS Partition Master, with Windows Disk Management and DiskPart, will increase your system volume in 4 ways. Check and follow the easiest way to extend your system partition with ease.

Part 1. Extend System Partition with Adjacent Unallocated Space

When there is unallocated space next to your system C drive, you may apply reliable partition manager software - EaseUS Partition Master, Disk Management or Diskpart to extend Windows 10 system volume. Check and follow the easiest way to get the job done.

Don't worry when the unallocated space is not behind your C drive. You may use the Resize & Move feature in EaseUS Partition Master and right-click partitions one by one between your C drive and the unallocated space so to move the unallocated space next to your system drive.

[Automated] Extend system partition with EaseUS Partition Master

EaseUS Partition Master is a comprehensive hard disk partition management software that supports extending system partition on Windows 10/8/7/Vista/XP 32 bit and 64-bit Operating Systems. Your data is completely protected during the whole process. 

Tutorial 1. Extend Windows 10 System Partition with EaseUS Partition Master

If your disk has adjacent unallocated space next to C drive, move to the 2 in Step 2 and start increasing C drive. If your C drive has low disk space error, follow Tutorial 2.

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.

Tutorial 2. Extend System C Drive with Low Disk Error in Windows 10

If your C drive is out of space and the computer warns you with a low disk space error. Follow the steps here to extend C drive with ease:

Step 1. Click "Adjust with 1-Click" to extend C drive.

When your C drive is out of space, you will see the Low Disk Space alert on EaseUS Partition Master. Click the Adjust button to extend it.

How to Adjust Low C Drive Space Step 1

Step 2. Click "OK" to extend C drive automatically.

By clicking "OK", EaseUS Partition Master will automatically allocate space to your C drive to solve the low space issue.

How to Adjust Low C Drive Space Step 2

Extra Option: You can also click "Manual Adjustment" to extend the C drive manually.

When turning to Manual Adjustment, select the C drive, and drag dots rightward to add more space to C drive. Click "OK" to confirm.

Manually Adjust Low C Drive Space

Step 3. Confirm to resolve low disk space in C drive

Click the "Execute Operation" button at the top corner and start all pending operations by clicking "Apply".

How to Adjust Low C Drive Space Step 3

EaseUS Partition Master enables you to extend C drive by moving space from D drive to C drive directly. Watch the video guide.

[Manual] Extend Windows 10 system partition with Disk Management

Using Disk Management to extend Windows 10 system partition, there must be contiguous space behind Windows 10 system partition. Otherwise, you cannot extend the system partition.
In this situation, you need third-party partition manager software like EaseUS Partition Master for help.

Let's see how to extend your Windows 10 system partition in Disk Management:

Step 1. Open Disk Management by right-clicking Windows icon and select "Disk Management".

Step 2. Right-click on the system partition that you want to extend, and select "Extend Volume" from the menu.

Extend C drive with unallocated space in Disk Manamgenent.

Step 3. Click "Next" and specify the size of the unallocated space that you want to add to the C drive, click "Next" to continue.

Click "Finish" to complete.

Confirm to extend C drive with Disk Management.

[Manual] Extend C drive on Windows 10 with DiskPart

Apart from Disk Management, another Windows built-in tool DiskPart also provides powerful partition management feature to help you extend the system C drive in Windows 10.

Note that DiskPart only works when the unallocated space is behind the system C drive on your PC.

Here are the detail steps:

Step 1. Right-click on the Windows icon and select "Search", type: cmd and hit Enter.

Step 2. Type: diskpart and hit Enter. Click "Yes" to open DiskPart.

Step 3. Type the following command and hit Enter each time:

  • list volume
  • select volume 1 (Replace 1 with the volume number of your system C drive.)
  • extend

Extend C drive in DiskPart.

or the following command:

  • list disk
  • select disk N (Replace N with the disk number of your system disk.)
  • list partition
  • select partition 2 (Replace 2 with the number of your system partition.)
  • extend size=X disk=N (Replace X with the specific size of the unallocated space and X is MB unit. Replace N with the disk number of your system disk.)

DiskPart extending C drive.

Step 4. Type: exit to close the DiskPart window when you finish extending the C drive.

Part 2. Extend Windows 10 System Drive without Unallocated Space

When there is no unallocated space on your system disk, what will you do?

If you tend to use Disk Management or DiskPart, shrink or delete the volume behind your C drive. And follow methods in Part 1 to add space to your C drive.

If you have free and unused space in other partitions on your system disk, you may apply EaseUS Partition Master with its Allocate Space feature to directly extend your system drive.

Note that this feature is currently available in its Pro and advanced versions. Therefore, to extend the system drive and make full use of space on your hard drive without deleting or shrinking partitions, upgrade EaseUS Partition Master to the Pro version first.

Step 1. Locate the Target Partition

To start extending partition, you should first locate the target partition and select "Resize/Move".

Select target partition to extend

Step 2. Extend the Target Partition

Drag the partition panel rightward or leftward to add unallocated space into your current partition and click "OK" to confirm.

choose another drive to allocate space

Extra Option: Get Space from Another Drive

If there is not enough unallocated space on your disk, right-click on a big partition with enough free space, select "Allocate space ".

Then select the target partition that you want to extend at the allocate space to column.

choose another drive to allocate space

Step 3. Execute Operations to Extend Partition.

Drag the dots of the target partition into the unallocated space and click "OK".

finish extending partition

Then Click the "Execute Operation" button and click "Apply" to keep all the changes. 


This page includes 3 partition management tools - EaseUS Partition Master, Disk Management, and DiskPart, to help you effectively extending C drive on Windows 10, 8 or even older system with or without unallocated space. 

If you have more questions about extending partition, you may check top concerned FAQs below to find direct answers:

1. Can I extend my C drive partition Windows 10?

The answer to "Can I extend my C drive partition in Windows 10"  is yes. EaseUS Partition Master, with Windows Disk Management and DiskPart, will increase your system volume in 4 ways. Check detailed steps on this page to extend your system partition with ease.

2. How do I extend my Windows partition?

Open Disk Management and right-click a partition next to your target drive, select Shrink Volume. Then adjust the size you do like to shrink and add to the target partition, click Next and Finish.

Then right-click on the target drive and select Extend Volume. Select to add all the unallocated space, click Next to confirm. Click Next and Finish to complete the process.

3. Why is Extend Volume disabled in Windows 10?

There are three reasons that may cause the Extend Volume option greyed out: 1. There is no unallocated space on your hard drive. 2. The target partition is FAT or other file systems, not NTFS. Only NTFS is a configured file system supported on Windows partitions. 3. There is no contiguous unallocated space next to or behind the target partition.

To resolve this issue, you will need to free up unallocated space and leave it next to your target partition. And convert FAT partition to NTFS.

For more concerned questions, you may use the search option on the right top corner of our website - https://www.easeus.com to search and find solutions. 

Was This Page Helpful?

author icon

Updated by Gemma

Gemma is member of EaseUS team and has been committed to creating valuable content in fields about file recovery, partition management, and data backup etc for many years. She loves to help users solve various types of computer related issues.

Read full bio

author icon

Written by Brithny

Brithny is a technology enthusiast, aiming to make readers' tech life easy and enjoyable. She loves exploring new technologies and writing technical how-to tips. On her spare time, she loves sharing things about her favorite singer - Taylor Swift on her Facebook or Twitter.

Read full bio

Product Reviews

TrustScore 4.7 | 49 reviews
  • I love that the changes you make with EaseUS Partition Master Free aren't immediately applied to the disks. It makes it way easier to play out what will happen after you've made all the changes. I also think the overall look and feel of EaseUS Partition Master Free makes whatever you're doing with your computer's partitions easy.

    Read More
  • Partition Master Free can Resize, Move, Merge, Migrate, and Copy disks or partitions; convert to local, change label, defragment, check and explore partition; and much more. A premium upgrade adds free tech support and the ability to resize dynamic volumes.

    Read More
  • It won't hot image your drives or align them, but since it's coupled with a partition manager, it allows you do perform many tasks at once, instead of just cloning drives. You can move partitions around, resize them, defragment, and more, along with the other tools you'd expect from a cloning tool.

    Read More

About EaseUS Partition Master

All-round disk & partition management software for personal and commercial use. Let it manage your storage drive: resize, format, delete, clone, convert, etc.

Product Reviews


Video Tutorial

Video poster

How to Partititon a Hard Drive on Windows 10/8/7

Was This Page Helpful

How Can We Help You

Find answers to common questions below.