Extend C drive or system partition in Windows 10

Tracy King updated on Feb 13, 2020 to Partition Master | How-to Articles

Page Content:

  1. 3 Ways to Increase C Drive Space in Windows 10
  2. Upgrade to a Larger Hard Drive Without Data Loss
  3. Tips to Extend C Drive in Windows 10
  4. Related Questions on Extending Partition Windows 10

Windows 10 C drive is out of space:

Windows 10 C drive out of space

When the C drive (system partition) is out of space, gets full or you get a low disk space warning, and hardware upgrades become unavailable shown as next image, what are you going to do? How to extend C drive or system partition in Windows 10? Follow tips below, you'll learn how to extend partition, especially to increase C drive in Windows 10. 

1 - Extend C Drive or System Partition in Windows 10 for Free

For users who want to extend C drive with a free and easy method, EaseUS Partition Master Free Edition is the right choice for you.

Solution 1. Let Free Partition Manager Software Help

As magic partition software, EaseUS Partition Master Free Edition is a FREE comprehensive hard disk partition management software to let you enjoy free with all the powerful functions:

  1. 1. Extend system partition
  2. 2. Resize and Move partitions
  3. 3. Copy Partition/Disk
  4. 4. Create, Deleted and Format partitions
  5. 5. Hide and Unhide partitions and more... 

This freeware works perfectly with hardware even with RAID and supports all Windows Operating Systems. Your data is completely protected during all operations.

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 Windows 10 is supported

Besides the basic and advanced partition manager features, EaseUS Partition Master also provides powerful partition recovery wizard to recover deleted or lost partition, cleanup and optimization for optimizing hard disk and clean up disk space, wipe data to permanently erase hard drive/partition and so on.

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
  1. The program may pop up a window to ask you to restart your computer after executing the operation, do as the software requires.
  2. Your computer will restart with a bigger system C drive and better computer performance on your Windows 10 PC.

Solution 2. Extend C Drive Windows 10 via Disk Management

There must be unallocated space behind the partition which you want to expand with Windows built-in Disk Management utility. Otherwise, you might find that the Extend Volume option is greyed out and not available.

Step 1. Right-click My Computer and choose "Manage -> Storage -> Disk Management".

Step 2. Right-click on the partition that you want to extend, and choose "Extend Volume" to continue.

extend windows 10 partition

Step 3. Set and add more size to your target partition and click "Next" to continue. 

Extend Windows 10 partition with Disk Managenent

Step 4. Click "Finish" to complete the process.

Solution 3. Extend C Drive Windows 10 via CMD

There is another tool named Diskpart which also enables you to manage your disk and partition. The Windows Command Prompt works the same as Disk Management. One important point is that inexperienced users should not rush to this method because a tiny mistake is able to do damage to the entire hard drive. 

Step 1. Press Windows + X keys and choose "Command Prompt (Admin)".

Step 2. Type the following commands and each one ends with "Enter" key:

Click to copy

In my case, the system C drive is Volume 1. If there is no unallocated space, you can't extend C drive in Windows 10 with this method.

extend c drive using cmd

2 - Upgrade to a Larger Hard Drive Without Data Loss

Clone and replace the old drive to a bigger one can also solve your problem. If you don't want to migrate other data on C drive, you can only migrate the Windows operating system to a new drive. 

Video Tutorial: How to migrate OS from HDD to SSD

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 Windows 10 is supported

If you want to replace the whole C drive both the system and the data, clone this drive with the help of EaseUS Partition Master. This feature enables you to move your system and data to SSD/HDD easily and quickly. Follow the steps below to clone your drive:


Step 1: Launch EaseUS Partition Master on your computer, right-click the partition you want to copy, and choose "Clone".

Clone Partition - Step 1

Step 2: EaseUS Partition Master will select the unallocated space on your computer as the target partition automatically. Check it and click "Next" to continue.

Clone Partition - Step 2

Step 3: Then you can adjust the size of the target partition according to your needs. After that, click "OK".

Clone Partition - Step 3

Step 4: Click the "Execute Operation" button in the top-left corner to review the changes, then click "Apply" to start cloning your partition.

Clone Partition - Step 3

Tips to Extend C Drive in Windows 10

In addition to these solutions, you may ask the way to extend C drive in Windows 10 without software. Here, you can learn some other tips to reduce the possibility of C drive full and increase C drive space.

1. Move the print spooler and page file to another drive.

2. You can also merge other partition into C drive for more space.

3. Apply professional partition manager software with Cleanup and Optimization feature can also speed up your slow computer, clean up those junk files and repair Windows system. This will save you a large amount of space on C drive and other partitions.

4. Empty recycle bin. Recycle bin is a storage room for all the files you delete from your PC. The deleted files remain there until you delete files from the recycle bin. Usually, the recycle bin takes up C drive space. That is to say, when you empty the recycle bin, you can increase a bit of disk space.

  • Right-click on the recycle bin icon located on your desktop and select "Empty Recycle Bin".
  • Or double-click on the recycle bin and click on the "Empty Recycle Bin" option located on top of the folder window.

Related Questions on Extending Partition Windows 10

In addition to extending the C drive, some people have asked related questions. Here are some examples:

1. Can we extend the C drive?

Yes, you can. You can use the third-party software, Disk Managemen or Diskpart to easily expand your C drive in Windows 10. Among them, EaseUS partition software is my recommendation. It can extend any drive easily and quickly.

2. How do I add storage from D to C?

Let EaseUS partition software help you. Launch EaseUS Partition Master and locate the target partition which you would like to extend. If there is unallocated space left on your disk, use the "Resize/Move" feature to extend partition. If there is no unallocated space on your disk, use the Allocate Space feature to extend the desired partition.

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 Windows 10 is supported

3. Why extend volume grayed out windows 10/8.1/7?

When you are using Disk Management to increase C drive space, you can right-click "Computer", choose "Manage" to go, then you can enter "Disk Management". If you see the Extend Volume option grayed out on your computer, it means that there is no unallocated space on your hard disk.

4. How to add space to C drive?

  • Launch EaseUS Partition Master.
  • Right-click on the System C: drive and select "Resize/Move".
  • Drag the system partition end into the unallocated space.
  • Click "Apply" to execute the changes and extend the C drive.

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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