Updated on May 13th, 2021

This post talks about how to change partition size in Windows 10/8/7/XP, and you can follow this guide to extend partition, shrink partition, split partition and resize partition without formatting or losing any data.

About changing partition size

When you set up computer with a large hard drive, you may want to create more than one volume so that you can use other partitions to separate operating system and installed applicated from individual data. If your hard drive is not properly partitioned, and now some partition on your disk is too small and some contains large amount of free space. You may want to resize partitions by moving free space between them without formatting volumes.

Have you ever met with low disk space issue on system partition in Windows 10/8/7? C drive (system partition) is running out of space and computer slows down. In this case, you can delete junk files and cache data, and uninstall non-frequently used programs so as to free up disk space. But this does not work that well, as system drive will run out of space soon. Therefore, the best solution is changing partition size for C drive.

Nowadays, it has become much easier to increase partition size or resize partition in Windows, as Windows partition tool is very effective and easy to use. Now users can easily extend C drive, split a partition, shrink volume or add unallocated disk space to partition without data loss.

Windows partition tools to change partition size

There are lots of ways to change partition size, for example, Disk Management provides functions to extend volume and shrink volume and users can use these functions to deal with some partition size issue; third-party partition tool enables to resize partition for complex situations.

• Windows Disk Management: Disk Management is Windows built-in utility to manage partition and disk. It contains functions like delete partition, extend volume and shrink volume, enables users to increase partition size by adding unallocated disk space. There are limitations on Disk Management, and not all partition can be changed size. For instance, as to extend partition, there should be contiguous disk space on the right side of the partition to be extended.
• Diskpart: as to advanced users, volume size can be changed via command lines which can be executed in Command Prompt or PowerShell.
• Free disk partition software: Partition manager software is capable of handling more complicated operations that Disk Management cannot do, for example, remove disk space among partitions, split partition, convert partition, convert MBR/GPT, convert dynamic disk to basic, etc. without data loss.

How to resize partition in Windows 10 Disk Management

In this example, we’ll use Disk Management to shrink partition size without data loss, and the process is easy to follow. If you want to extend partition size here, you should make sure there is adjacent free disk space, if not you nee to delete a partition to get unallocated space. To shrink a partition, you can follow these steps:

Step 1: Launch Disk Management console in Windows 10 by right-clicking Start button and choose Disk Management.

Step 2: Right-click on the partition you want to reduce its size, and choose Shrink Volume, as below:

Step 3: Enter the disk size in MB you want to shrink from the pop-up window and click Shrink button.

Note: you cannot shrink a volume beyond the point where any unmovable files are located. See the “defrag” event in the Application log for detailed information about the operation when it has completed.

How to change partition size with free Windows partition tool?

DiskGenius Free is a free disk partition program which is designed for disk & partition management, data backup and data recovery. It can resize partition, extend partition, shrink partition and split partition without losing data. With this wool you can change partition size for NTFS, exFAT, FAT32, EXT4, EXT3 and EXT2 volumes via more flexible and simple process. Let’s see how to resize partition in Windows.

Step 1: Download DiskGenius Free Edition, install and launch it from your computer. Right-click on the partition you want to change size and choose Resize Partition.

Note: there are two other options available: extend partition and split partition. Extend partition can increase partition size by moving free space from other partition, while split partition can divide one partition into two partitions. As to resize partition, you can either increase or shrink its size. 

Step 2: Set partition size to be moved between these two partitions and click Start button.

You can move the cursor between partition bars to decide disk space to be moved.

Step 3: Click Yes to continue when DiskGenius asks confirmation for rest operations. Wait for the process to complete.

Apart from increasing/resizing partition size via moving disk space among partitions, DiskGenius is able to add unallocated space to any existing partition without data loss. Thus, if your hard drive contains unallocated space, you can either create new partition or add it to partition. Since Disk Management can add unallocated space to adjacent partition, you can use DiskGenius to add free space to other partition.

Launch DiskGenius and right-click on free disk space and choose Allocate Free Space.

Click Yes button from the pop-up window and DiskGenius starts to move free space to selected partition.

Conclusion on changing partition size

Windows Disk Management and diskpart commands provides limited features to change partition size, and you need to use third-partition disk partition freeware to resize partition under complicated situations. This guide includes various methods to increase or decrease partition size without data loss, and you can try them to manage partition size on your computer to make your disk organized. So far, you may feel it is very easy to resize partition in Windows 10/8/7/XP. If you have any question or need any help when resize Windows partition, please feel free to contacting us.