Extend volume not available in Windows Server 2022 is not a big problem. You can get one more ways to fix it based on your situation from this post.
In a Server device, lots of users might find that no matter how big capacity they leave for a C drive, the C drive will always be devoured by the boomed data. This will have a great effect on the computer's performance, so if the capacity of your present hard drive is insufficient, you will need to expand the little volume or possibly switch to a larger disk.
“Extend Volume” is designed by Microsoft in Disk Management to help users adjust the size of partitions. However, it’s often greyed out in 2 circumstances.
1. There is no unallocated space on your hard disk.
2. There is contiguous unallocated space, but it is to the left of the partition to be extended. The unallocated area should be on the neighboring right side.
Due to only an empty space which is on the right behind of the target partition can be added, so if that space doesn’t have important data, you can delete it and turn it into an unallocated space for extend volume.
Right-click “This PC” and choose “Management”, click “Disk Management” to open it.
Make sure the partition on the right side of C drive doesn’t have any data important, right click it, choose “Delete Volume”.
In the prompted, you’ll be asked to make sure again the data of this partition is backed up. Click “Yes” if you’re ready.
Now the partition is an unallocated space, and the “Extend Volume” of C drive is available.
What if the partition right behind the C drive is quite important? What if you are the second circumstance we mentioned above? Even if you decide to delete the partition, you still need to back up your data, and it will consume much time. So, to save your time and cut all redundant operations, you can try AOMEI Partition Assistant Server.
No matter which situation you meet we mentioned above, this Server manager can perfectly solve “Extend Volume” not available in Server 2022, 2019, 2016, 2012(R2), and in Windows 11, 10, 8, 8.1, 7, XP.
The "Merge Partition" functionality can solve your problem if the unallocated space is not contiguous to the target partition; and if your disk doesn’t have unallocated space, you can use “Allocate Free Space” to directly share the free space from one drive to C drive. Both features won’t cause data loss.
We'll go through two functions step by step.
Right-click on the partition (here is C: drive) you want to extend, choose “Advanced” and select “Merge Partition”.
In the pop-up window, tick the box of unallocated space and the C: drive. And then click “Next” button to continue.
Now you can preview the unallocated space behind D: partition is added into C: drive. To execute, click “Apply” and "Proceed".
Then, just need to wait for a while, the selected space will be added to C drive.
Users can transfer free space from one partition to another to increase the size of the target partition. They do not need to first resize or shrink another partition to gain free space; instead, they only need to simply transfer free space from the source partition to the destination partition to increase the partition size. It is incredibly simple and quick.
Right-click the partition which you want to allocate free space from and select "Allocate Free Space".
The size of the free space that you wish to cut from D partition will be displayed in a pop-up window, and this free space will be instantly put to the destination partition.
Click "Apply" to execute this operation. And since you extend C drive, you may need to reboot your computer.
After this post, “Extend Volume” not available in Windows Server 2022 will no longer be a problem for you. AOMEI Partition Assistant Server is a professional Server management tool, you can also use it to transfer OS to another disk, convert to GPT/MBR… And if you are an enterprise user, there is Partition Assistant Technician Edition that allows you use this tool on unlimited computers in multiple locations.
Why can't I extend volume with unallocated space? Unallocated space is not always adjacent to the volume being extended. When you create a new partition or remove an existing partition on a hard disk, the unallocated space that results may not be next to the volume you wish to enlarge. Windows cannot expand the volume to the unallocated space in this instance.
How to move unallocated disk to C? If the unallocated partition is on the right behind the C drive, you can directly add this space to the C drive. However, if it's not on the right location, you could only use third-party tool to add it into the C drive.
How to extend drive with CMD? If the unallocated space is on the right location, you can direcly run CMD as administrator and type "diskpart" in the Run box, then press Enter on the keyboard. Type "list volume" and press Enter on the keyboard to display the existing volumes on the computer. Type "select volume c" and press Enter on the keyboard to focus on volume c. Type "extend [size=n]" to extend volume c to disk n of size n.