EaseUS Partition Master

A simple partition tool to manage disk space in Windows 10

How to Extend C Drive in Windows 10 Without Formatting

Updated by Cedric Grantham on Mar 16, 2021
Written by Daisy

Have you ever receive the low disk space warning when you boot your computer or use a hard drive? When this error message pops out, it means that your hard drive is running out of space.

C drive low disk space

Insufficient disk space will affect the normal use of a computer, the system disk space shortage is particularly serious. When your C drive is full and out of space, you will suffer low work efficiency, the system will run unstable, and you may not be able to download and install new software or use the installed programs.

If you are in this situation, don't worry. One way to solve this problem is to extend system partition to improve computer performance. How to extend C drive in Windows 10/8/7? EaseUS partition manager offers you the simplest way to increase C drive.

How to Extend C Drive with EaseUS Partition Master

EaseUS Partition Master is an all-in-one partitioning tool that is fully compatible with Windows 10/8.1/8/7/Vista/XP. With this program, you can extend C drive effortlessly with or without unallocated space.

When there is unallocated space on your system disk, you can simply resize C drive to get more space. When there is no unallocated space on your hard disk, you can apply EaseUS partition manager to increase C drive with free space on other partitions. 

You can make the following hard drive managements without data loss and any effort with EaseUS disk management tool. 

EaseUS Partition Master

  • Resize/move partitions, create, format, delete, and merge partitions, and wipe disk data to protect privacy
  • Copy and clone an entire disk to another, migrate OS to SSD to speed up Windows without reinstalling
  • Convert a logical partition to primary or primary partition to logical, FAT to NTFS partition, MBR disk to GPT, or GPT disk to MBR

1. Extend C Drive Automatically in 1-Click with Smart Space Adjustment Feature

EaseUS Partition Master has the "Adjust with 1-Click" function to extend a drive that is out of space automatically. When your C drive is out of space, you will see the low disk space alert on the software interface. Then, with only a few clicks, you can resize and expand your C drive without any data loss.

Step 1. Launch EaseUS Partition Master and click "Adjust with 1-Click."

When your C drive is out of space, you will see the Low Disk Space alert on our product.

How to Adjust Low C Drive Space Step 1

Step 2. Click "Proceed" to adjust space automatically.

EaseUS Partition Master will automatically adjust your C drive to solve the low space issue. Click "Proceed" to continue.

How to Adjust Low C Drive Space Step 2

You can also click "Manual Adjustment" to extend the C drive manually if the Smart Space Adjustment cannot meet your needs.

When turning to Manual Adjustment, the result of smart adjustment will be retained as the starting point for manual adjustment. Select the C drive, and drag dots to add more space to C drive. Then click "Proceed" to continue.

Manually Adjust Low C Drive Space

Step 3. Execute operations.

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

If you want to manually expand your C drive, you can use the Allocate Space option of EaseUS Partition Master to move space from D drive to C drive or transfer free space from any other available drive to the system drive.

2. Extend C Drive Without Formatting Using Resize/Move Partition Option

When there is no unallocated space on your disk and you don't want to delete or format the hard drive, you can use EaseUS partition management software to extend C drive and by its "Resize/Move partition" feature.

Step 1. Launch EaseUS Partition Master

Run EaseUS Partition Master

Step 2. Add space to the System C drive

1. Shrink partition and leave unallocated space for extending C: drive:

  • Right-click on a partition next to the C: drive and select "Resize/Move".
  • Drag the end of the partition that is next to the C: drive and shrink it, leaving unallocated space next to the system C: drive, and click "OK".

2. Right-click on the System C: drive and select "Resize/Move".

Extend System partition

To add space to the C: drive, drag the system partition end into the unallocated space.

Add space to C drive

Step 3: Confirm to extend system C drive

Click the "Execute Operation" button, it will list the pending operations, and click "Apply" to execute the changes and extend the C drive.

Confirm to extend system C drive

How to Extend C Drive When There Is Adjacent Unallocated Space 

As mentioned before, you can use EaseUS Partition Master to add space to the C drive in complicated circumstances. For example, there is no unallocated space on your disk, or the unallocated space is not adjacent to the C drive.

However, if you are in this simple case, that is C drive has adjacent unallocated space, you have two ways to expand C drive.

1. Extend C Drive by Using Disk Management

Windows 10 Disk Management can finish some basic disk management, such as delete/format/create/shrink a partition. Here are detailed steps for extending the C drive.

If the unallocated space is not adjacent to the C drive on its right side, the Extend Volume will grey out. And you need to apply EaseUS Partition Master to expand C drive.

Step 1. Right-click the Windows button, choose "Disk Management".

start disk management

Step 2. Right-click C drive and choose "Extend Volume...".

extend C drive with disk management

Step 3. Follow the on-screen instructions to finish extending C drive. 

expand C drive

2. Increase C Drive with Diskaprt Utility

When there is a contiguous adjacent unallocated space behind the C drive, you can also increase C drive by using the Diskpart tool in CMD.

Step 1. Press the Win+R buttons to open the Run dialogue. Then, type diskpart and press Enter.

Step 2. Type the following command lines in order and press Enter after each one.  

list disk
select disk x
(x is the number of the system disk)
list partition
select partition x 
(x is the number of C drive)
extend size=x disk=N (x is the size in MB you want to add to the system partition, N is the number of your system disk.)

extend C drive in diskpart

EaseUS Partition Master - A Simple C Drive Partition Extender

After reading this guide, we believe that you've learned how to extend C drive in every way. If there is adjacent unallocated space right behind the C drive, you can use the Windows built-in tools - Disk Management and Diskpart to extend C drive with ease.

If things get a little more complicated, then, EaseUS Partition Master is your best choice. It can easily extend C drive with different solutions, such as:

  • Extend C drive automatically with "Adjust with 1-Click" feature when it is in low disk space.
  • Allocate space from other partitions to C drive without deleting.
  • Quickly expand C drive even the unallocated space is not adjacent to the system drive.

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Updated by Cedric Grantham

Cedric Grantham is one of the senior editors of EaseUS who lives and works in Chengdu, China. He mainly writes articles about data recovery tutorials on PC and Mac and how-to tips for partition management. He always keeps an eye on new releases and likes various electronic products.

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Written by Daisy

Daisy has been working as a technical writer for eight years. She specializes in making the complicated easy. She believes that technology should bring users satisfaction, not annoyance, so she writes a lot to help people overcome their tech troubles.

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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.

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  • 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.

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  • 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.

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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.

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

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