How to Increase Space in C Drive on Windows 10/8/7 Without Losing Data or Formatting

Daisy updated on Sep 17, 2020 to Partition Manager | How-to Articles

"How to increase space in C drive without deleting data? Recently, a 'low disk space' pop-out balloon keeps appearing in the Systray, warning me to extend C drive space. I can neither format the C drive nor delete other partitions as I have data saved on all the partitions. So how can I possibly increase C drive space without formatting or deleting partitions?"

On the Windows computer, the running speed of an operating system largely depends on the available free space in C drive. However, with the increasing number of installed software and its corresponding data storage on C drive, your system partition will run out of space, and your computer will have worse performance.

los disk space on Windows 10

Usually, over 90% of users want to extend C drive space because the free space approached the threshold of 200MB, 80MB, and 50MB. You may have tried to delete the unnecessary files, uninstall programs, or clean up the recycle bin to get some spare room in the C drive. But these are only temporary fixes. It won't be long before your C drive is full again. Then, how to increase space in C drive and completely solve the C drive low disk space problem? Read this tutorial in-depth. 

How to Increase Space in C Drive Windows 10 by Resizing Partition

To increase C drive space to speed up Windows 10, three solutions are practical: using EaseUS Partition Master, Windows Disk Management, and Command Prompt.

1. Increase C Drive Space Without Losing Data via EaseUS Partition Master

Being one of the most intelligent disk/partition management software, EaseUS Partition Master can extend C drive space in two ways.

  • First, if you have unallocated space on the same hard disk as the C drive, you can opt for the "Resize/Move" feature to merge the free unallocated space with the C drive.
  • Second, it doesn't matter even you don't have any unallocated space. You can simply use the "Allocate Space" to allocate some space from those non-system partitions to the system C drive without causing damage to saved data on your PC.
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 Windows 10 is supported

Step 1. Locate the Target Partition

To start extending partition, you should first launch EaseUS Partition Master and locate the target partition which you would like to extend.

Step 2. Extend the Target Partition

1. Right-click on the target partition which you would like to extend and select "Resize/Move".

Select target partition to extend

2. 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

3. If there is no or not enough unallocated space on your disk, use the advanced partition resizing function to directly allocate free space from other partitions to the target drive without deleting or formatting.

Find the "Allocate XX space from" option, then click "Select partition". Choose the partition from which you want to allocate space. Drag the partition panel rightward or leftward to resize the partition you want to extend. Then click "OK" to confirm.

choose another drive to allocate space

Step 3. Execute Operations to Extend Partition

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

finish extending partition

Except for resizing partition, EaseUS Partition Master provides more one-stop disk partition features. For example, you can clone disk, merge adjacent and non-adjacent partitions, create/delete/format partition, wipe data, and convert disk/partition conversion (e.g., convert MBR to GPT).

2. Extend C Drive Space in Disk Management by Deleting Partition

Disk Management comes with Windows and has many functions to manage disks, including extend volume, shrink volume, format partition, delete partition, etc.. You can use the "Extend Volume" option for increasing C drive space if you don't want to use the third-party EaseUS Partition Master to extend C drive.

Yet, there is a condition when extending C drive via Disk Management; that is, there needs to be some unallocated space very behind the C drive. Otherwise, the extend volume will be greyed out.

If there is no unallocated space, how to increase the space in C drive? We should first create unallocated space by deleting partitions and make sure it locates right behind C drive. Then, extend C drive with the unallocated space. Do it by following the guides below.

Next, we will show an example of how to increase C drive space by removing D drive, which is very behind C.

Step 1. Open Disk Management, right-click partition D, and choose "Delete Volume". When the process finishes, we can see there is unallocated space and locates right behind C drive.

delete D drive to increase C drive size

1. Deleting a partition will lead to data loss. Make sure you have backed up the crucial data on the partition or moved files to another safe place.
2. If the unallocated space is not enough, you can continue to delete the next partition to create more unallocated space.

Step 2. Now, right-click on C drive and select "Extend Volume". Extend Volume Wizard will pop up. Follow the on-screen guide to complete increasing C drive.

extend C drive in disk management

3. Increase Space in C Drive Using Command Prompt

If you are a computer expert, you can use the command lines to extend C drive. Otherwise, be careful to run these commands to make sure you can move more space to C drive without any extra issue, or use the automatic EaseUS partition manager to help you out.

If there are any misoperations that result in data loss, remember to immediately use data recovery software to help you get back files.

If there is an adjacent unallocated space behind the system C drive, you can follow the steps below: 

Step 1. Type diskpart in the Search Bar and hit enter.

Step 2. Input these commands orderly, and press Enter after each command line.

Click to copy

If there is no unallocated space right behind the system C: drive, follow the below steps:

Step 1. Type diskpart in the Search Bar and hit enter.

Step 2. Input the following commands one by one and press Enter after each command line.

Click to copy

More Useful Methods on How to Increase Space in C Drive 

In addition to moving space from another drive to C drive to increase the size of C drive, you can free up space in C drive by performing system clean up regularly and transferring installed programs to another drive. Furthermore, you may also upgrade the system disk to a bigger HDD or SSD to solve the low disk space and slow running problems thoroughly.

1. Run System Cleanup to Increase C Drive Space

Useless junk files, outdated system data,  temporary files, cache data, etc., all these files will take huge space on C drive. EaseUS Tools M enables you to clear these junk files on C drive quickly within a few clicks.

Step 1. DOWNLOAD and install EaseUS Tools M. Select "System Cleanup" on the main screen.

click system cleanup

Step 2. Select the type of junk files you want to scan and click "Analyze".

analyze junk files

Step 3. Identify and select useless files and click "Clean up" to remove those files from your PC or laptop.

click clean up to remove junk files

2. Move or Delete Large Files to Increase Space in C Drive 

You can check the C partition, manually copy and paste saved big files on the C drive to other secure free partitions. 

You can follow the below steps to locate and move the saved big files to other partition:

Step 1. Press "Windows + I" to open Windows Settings, click on "System" and " Storage".

Step 2. Under "Storage",  select the C: drive to analyze. (Note that the "This PC" drive is the main computer's hard drive where Windows 10 is installed.)

Check C drive storage.

Step 3. Click the Item name such as "Documents", Desktop, Apps & games, etc. to locate the saved big files. Click "View" to check and copy the specific saved big files on C drive.

Locate saved big files.

Step 4. Move these files to another non-system partition by "Copy & Paste". Then delete the original useless files on C drive.

3. Transfer Installed Programs from C Drive to Another Drive

As you know, installed programs and software will also eat up much space on the C drive. Professional PC transfer software such as EaseUS Todo PCTrans will effectively migrate your installed programs to another drive without reinstallation. 

Follow this link to learn how to transfer programs from C drive to D drive to free up space in C drive.

4. Upgrade System Disk and Migrate OS to HDD/SSD

When the system disk gets old after using it for a very long period, the C drive will get full, and the computer performance will slow down. To resolve this issue, the best way is to upgrade and replace the system disk with a bigger new hard drive.

EaseUS Partition Master enables you to effectively upgrade system disk and migrate OS to HDD or SSD by cloning disk. By doing so, you'll be able to move everything, including Windows OS, saved data, installed programs to the new hard drive at one time without worrying about any startup issues. Also, you'll be able to get more free space for C drive.

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 Windows 10 is supported

Note: The operation of migrating OS to SSD or HDD will delete and remove all existing partitions and data on your target disk. If you saved important data there, back up them to an external hard drive in advance.


Step 1: Run EaseUS Partition Master, select "Migrate OS" from the top menu.

select migrate os

Step 2: Select the SSD or HDD as the destination disk and click "Next".

Warning: the data and partitions on the target disk will be deleted. Make sure that you've backed up important data in advance. If not, do it now.

Then click "Migrate" to continue.

select the destination disk

Step 3: Preview the layout of your target disk. You can also click the disk layout options to customize the layout of your target disk as you want. Then click "Proceed" to start migrating your OS to a new disk

preview the lay out

How to Increase C Drive Space Summary 

This page covers all the effective solutions to increase C drive space in Windows 10/8/7. To optimize your hard disk and partition to enhance computer performance, we highly recommend you equip your computer with EaseUS Partition Master.

With this partition management tool, you can take full advantage of your disk space without effort by resizing, merging, creating, formatting, deleting, cloning, migrating, and converting partitions.

Download Now

 Windows 10 is supported

How to Increase Space in C Drive FAQs

We have covered many ways to increase space in C drive above. If you also have any of the following questions, check the brief answers. 

How do I make my C drive bigger?

If there is no important data on anther partitions, you can delete the partition behind the C drive to make unallocated space to extend C drive in Disk Management:

Step 1. Press Windows + R to open Run, type diskmgmt.msc and press Enter to open Disk Management.

Step 2. Right-click D drive and select "Delete Volume", then it will be changed to Unallocated space.

Step 3. Right-click C drive and select "Extend Volume".

Step 4. Click "Next" and follow Extend Volume Wizard to increase C drive.

How do I increase the size of my C drive in Windows 10?

The simplest ways to increase the size of C drive in Windows 10 is using EaseUS Partition Master to move space from D drive to C drive:

Step 1. Right-click on the D partition with enough free space and select "Allocate Space" to allocate the free space to the C drive.

Step 2. Select the C drive that you need to extend. Drag the partition panel rightward to add space allocated from the source partition to the target one. Then click "OK" to confirm.

Step 3. Click the "Execute Operation" button and click "Apply" to start the process of moving free space from D drive to C drive.

How can I increase C drive space without formatting?

You can increase C drive space without formatting with the Resize/Move function of EaseUS partition management software:

Step 1. Download and launch EaseUS Partition Master.

Step 2. Right-click on the target partition which you would like to extend and select "Resize/Move".

Step 3. Drag the partition panel rightward or leftward to add unallocated space into your current partition and click "OK" to confirm. You may also use the Partition size option to adjust and extend the target partition.

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Frequently Asked Questions

Why Choose EaseUS Partition Master?

"I've used Partition Master Professional many times to create, delete, format, move, rename, and resize partitions."PCWorld

"Partitioning tools have come a very long since the days of complicated command line utilities and EASEUS Partition Master is one of the most advanced programs available."TECH ADVISOR

"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."Lifewire

Will the "Migrate OS" feature transfer the Windows system files only or the whole C drive?

To ensure that the migrated system will boot normally, the Migrate OS feature will transfer all the files in the system and the boot partitions. Generally, the boot partition is the C drive so the transfer will include all the files in C.

Does EaseUS Partition Master license apply to multiple computers?

The license of Partition Master Professional and Server editions can be used on 1 computer only, while that for for the Technician and Unlimited editions can be used on multiple machines.

What is the difference between EaseUS Partition Master Trial version and the Free version?

Free is for home users only, with most basic functions available such as partition resize and clone. While trial can help you understand how this product works and test what a full license can do on a business or server OS machine.

Will it cause any data loss after resizing the partition in EaseUS Partition Master?

Generally, it will not cause any data loss or boot issue by resizing a partition. However, in order to protect your data, we suggest that you backup the partition before resizing, in case of any unexpected situations such as power outages, computer hardware failures, etc. You can use EaseUS Todo Backup to backup the partition and its trial version is fully functioned for 30 days.

What should I prepare before resizing the partition?

On the partition that is going to be operated, there might be some files being occupied by other programs. To ensure a successful operation, we suggest that you close all the unnecessary software before resizing that partition. Otherwise, EaseUS Partition Master will detect the partition being locked by the other software and require a reboot to resize the partition under boot mode.

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.

Video Tutorial

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