How to Resize a Partition Without Losing Data
Resizing partitions is one of the most common disk management tasks. Whether your C: drive is running out of space or you want to create room for a new partition, modern tools make it possible to resize partitions safely without losing any data. This guide covers both the built-in Windows method and third-party solutions for scenarios where Disk Management falls short.
Quick Answer
Can I resize a partition without losing data?
Yes. Use Windows Disk Management to shrink a partition (right-click, Shrink Volume) or extend it into adjacent unallocated space (right-click, Extend Volume). For non-adjacent space or moving partitions, use a free tool like AOMEI Partition Assistant.
Method 1: Using Windows Disk Management
Disk Management handles basic resize operations safely but has limitations. It can only extend a partition into unallocated space that is immediately to its right. It cannot move partitions or merge non-adjacent free space.
Open Disk Management
Press Win+R, type diskmgmt.msc, and press Enter.
Shrink: Right-click the partition and select Shrink Volume
Enter the amount to shrink in megabytes. Windows protects your data — you cannot shrink below the space used by files.
Extend: Right-click the partition and select Extend Volume
This option only works when unallocated space is directly to the right. Select the amount to add and complete the wizard.
Method 2: Using AOMEI Partition Assistant
When Disk Management cannot handle your resize scenario — such as extending C: drive when the unallocated space is not adjacent — a free third-party tool like AOMEI Partition Assistant solves the problem. It can move partitions, merge non-adjacent space, and resize in ways that Disk Management cannot.
Download and install AOMEI Partition Assistant Standard (free)
Download from the official aomei.com website. Install and launch the application.
Right-click the target partition and select Resize/Move
A visual editor appears showing the partition. Drag the edges to resize or drag the center to move the partition position.
Click Apply to execute the changes
AOMEI previews all pending changes before applying. Review the operations and click Proceed. A restart may be required for system partitions.
Safety Precautions
Back up important data before any resize operation — even though modern tools are reliable, hardware failures during the process can cause data loss
Ensure your laptop is plugged into power — a power loss during partition resizing can corrupt the file system
Close all applications using files on the partition being resized to avoid file lock conflicts
Do not force restart your computer during a resize operation — wait for it to complete even if it appears to stall