How to Resize Partitions Using Windows Disk Management
Resizing partitions allows you to reclaim unused space or expand a volume that is running low on storage. Windows Disk Management supports both shrinking and extending partitions without formatting or data loss. This guide walks you through the complete process for Windows 10 and Windows 11.
Quick Answer
Can I resize a partition without losing data?
Yes. Windows Disk Management can shrink and extend partitions without affecting your files. To shrink, right-click the partition and select Shrink Volume. To extend, you need unallocated space adjacent to the right of the target partition, then right-click and select Extend Volume.
How to Shrink a Partition
Open Disk Management
Press Win+R, type diskmgmt.msc, and press Enter.
Select the partition to shrink
Right-click the partition you want to reduce in size and select Shrink Volume.
Enter the shrink amount
Windows calculates the maximum shrinkable space. Enter your desired amount in MB and click Shrink.
Verify the result
Unallocated space appears next to the shrunk partition. This space can now be used to create a new partition or extend another volume.
How to Extend a Partition
Ensure unallocated space is available
You must have unallocated space immediately to the right of the partition you want to extend. If it is not adjacent, you need a third-party tool.
Right-click the partition
Select Extend Volume from the context menu to launch the wizard.
Specify the extension size
Choose how much unallocated space to add to the partition and click Next, then Finish.
Why Extend Volume is Greyed Out
The most common issue users encounter is the Extend Volume option being greyed out. This happens when there is no unallocated space directly to the right of the partition you want to extend. Disk Management can only extend into contiguous unallocated space. If the free space is on the other side of a partition, you need a third-party partition manager like AOMEI Partition Assistant or EaseUS Partition Master to move partitions and merge non-adjacent space.