By Cherry / Last Updated July 26, 2019

Scenario: I have a laptop which has a very serious problem about the C Drive recently. I totally understand that there are something wrong with my system partition. Finally I got that the C partition is running out of space while the D drive is empty. I tried renaming C to D, and vice versa to extend the size of C, but it didn’t work. Is there any way that I can make the C drive bigger by taking space from D partition?

What Should We Do to Make the System Partition Bigger

It’s definitely a wise idea that it can make C partition bigger by taking space from D drive. But, I have to say that renaming C to D won’t solve the problem and it would cause some new troubles. C drive contains many data, and after this kind of operation, the system wouldn’t be able to find them. Then, if we have the same trouble, what should we do?

We all know that C drive is related to the system operating, and it requires a large volume. There are many data on it so that it could be easy to run out of the space. If the system partition has no free space, we may consider that if we can extend the volume by taking space from other partition. We can use the extend volume and shrink volume of disk management to solve it. But sometimes the button is under the grey status, so that we need other software to help us, and AOMEI Partition Assistant is a good choice for the multiple methods and the simple steps.

The Steps to Finish the Job by Using AOMEI Partition Assistant

With the help of AOMEI Partition Assistant Professional, it could be easier to do. Here, I will use two methods of AOMEI Partition Assistant to explain you the details, for it can do the job in a few steps and without losing data.

Before you do, there are some tips for you:

  • Backup is always required, in case of some inevitable situations. For example, the computer loses power or goes down.

  • If the partition has running applications, AOMEI Partition Assistant will suggest you to close them or perform the operation under PreOS Mode.

1.Allocate Free Space

Step1. Install and launch AOMEI Partition Assistant Professional, right click D partition and select “Allocated Free Space”.

Allocate Free Space

Step2. Resize the size that you want to add to C drive, and click “OK”, you will see the C drive become bigger while the D drive is smaller than before.

Resize The Size

Step3. Click the “Apply”, the whole process are finished.

Apply The Operation

2. Resize Partition

Step1. Install and launch AOMEI Partition Assistant Professional, right click D: and select “Resize Partition” as the screenshot as following.

Resize Partition D

Then, drag & drop the arrow in the interface to resize the D: in order to get an unallocated space. Only if the unallocated space adjacent the C:, it will be extended.

Arrow Partition D

Click “OK” and it will produce an unallocated space.

Unlocated Space

Step2. Right click the C: and select “Resize Partition” as the first step. It will show an interface like the screenshot. Then, drag & drop the arrow, click the “OK”, the C drive could be bigger than before.

Resize Partition C

Step3. After those steps, we can barely see the C partition is bigger while the D drive is smaller than before. Don’t forget to click the “Apply” as the picture shows. Only when you apply to commit this command, the size will be change successfully.

Finish Click


This partition assistant will keep your data safe. It will operate without restarting the computer, so it will be save the time. It’s much safer and faster.

The steps are very simple and it’s very easy to learn. Considering the difference of the different edition, some of them need to pay, but you can also download the free edition..

There are also another ways to make system partition bigger by taking space from D drive. Such as the “merge partition” features of AOMEI Partition Assistant.

Related Articles:

The Ways to Extend Volume in Windows 10

How to Extend Partition using Diskpart?

How to Increase Partition Size of Windows 10 Easily and Safely?