By Cherry / Last Updated June 28, 2021

Do you need to increase partition size for Windows 10?

Is your computer running slower and slower after upgrading to Windows 10? It is a symbol that your system partition is not enough to store the applications. Thus, you have to find a way to increase the system partition size for running Windows 10 in a normal or faster speed. If your system partition is running out of space, to increase partition size is necessary.

How to increase partition size in Windows 10?

There are many ways for you to increase partition size for Windows 10.

Increase partition size for Windows 10 with Disk Management

Windows 10 has a tool called Disk Management for managing disks. It has great features extend/shrink volume. To increase partition size, you can open Disk Management by right clicking Start menu -> click Disk Management. You can see the main state of your partitions. If there is an unallocated space adjacent to the system partition, right click C: drive, select Extend Volume to increase the system partition with this unallocated space. But there is one thing that you must know--Extend Volume of Disk Management can only supports to extend partition which has unallocated space neighbor to the partition at the right side. Someone may have a question, what if there is no unallocated space here or the unallocated space is at the left side? Well, Disk Management cannot solve those questions. Fortunately, you can solve those questions by using a third-party software.

Increase partition size for Windows 10 with AOMEI Partition Assistant

AOMEI Partition Assistant is a great powerful tool for managing disks. It can resize partition, create partition, delete partition, format partition, etc, and it supports almost all the Windows system no matter Windows PC system, or Windows Server. Different clients have different versions to get a better performance. For PC users, here we highly recommend you AOMEI Partition Assistant Standard, a free edition which is enough for you to manage your disks. It supports almost all the Windows PC operating system like Windows XP/Vista/7/8/8.1/10.

To increase partition size for Windows 10, AOMEI Partition Assistant provides at least three methods. But first, you need to download AOMEI Partition Assistant, install and launch it.


You can see there is no unallocated space behind C: drive. That means you cannot increase system partition with Disk Management. AOMEI Partition is full of magic. It can increase the C: drive in a few steps.

Method 1. Merge Partitions. Right click C: drive, select Merge Partitions. Then, you can merge the C: drive and the adjacent drive(usually D: drive) and all the unallocated space even they are not beside the C: drive. Click Apply after all the operations.

Method 2. Move free space from other partitions. Like the picture shows, the D: drive has many free space, you can right click D: drive and select Resize Partition or Split Partition to move some free space out, then right click C: drive and click Resize Partition or Merge Partition to extend the C: drive with this free space. Click Apply.

Method 3. Following the Extend Partition Wizard to increase partition size for Windows 10 step by step.

Besides, AOMEI Partition Assistant provides partassist.exe utility, which you can resize partition at the command prompt with command lines. You can also increase partition size for Windows 10 with command lines.