

When unallocated space before the partition you need to extend (like the screenshot shows), you can’t make it contiguously behind the partition in Disk Management and then extend partition. Then unallocated space is on the left of the to-be-extended partition. To move partition in Window Server 2019, 2016, 2012 (R2), 2008 (R2), you can try AOMEI Partition Assistant Server. Note: AOMEI Partition Assistant Professional is for Windows 11/10/8.1/8/7, XP, and Vista. And you can use Disk Management to extend it successfully. Wait for a while and you’ll find that unallocated space has been adjacently behind C drive. Click “Apply” and “Proceed” to commit the operation. In the pop-up window, drag the partition to the right side and click “OK”. Right-click the partition that separates the partition that’s going to be extended and the unallocated space then choose “Move Partition”. Install and run the tool and all the disks will be listed. It's available to download the demo version of AOMEI Partition Professional and have a try! If you don’t want to suffer from data loss, you can use a third-party partition manager- AOMEI Partition Assistant Professional, to move partition and make the unallocated space contiguously behind the to-be-enlarged partition. What you should know is that all data on the deleted partition will be lost. Then, right-click the to-be-extended partition and you’ll find “Extend Volume” is enabled. In Windows 10 Disk Management, right-click the partition that you need to delete and choose “Delete Volume”. In such a condition, you can delete the partition(s) between the to-be-extended partition and the unallocated space. The unallocated space is on the right of the partition that you’ll enlarge, but there is a partition (partitions) between them. Here list different situations and corresponding solutions of Windows 10 Disk Management “Extend Volume” greyed out. To enable “Extend Volume” function in Windows 10 Disk Management, there should be unallocated space adjacently behind the to-be-extended partition and the goal partition should be formatted with NTFS. Why is “Extend Volume” option greyed out in Windows 10 and how to fix it? Why I can’t extend C drive with unallocated space? Is a way to fix Extend Volume greyed out? Any advice is appreciated!”

I right-click C drive but only find that Extend Volume option is disabled. I shrink D drive and get unallocated space behind D drive.

I try to extend C drive in Disk Management as I find that it is almost full. Extend Volume greyed out in Windows 10 Disk management
