Cannot extend C drive in Windows Server 2012 (R2) Disk Management
From Windows Server 2008, Microsoft provides GUI function in Disk Management to change partition size. It is great improvement to previous editions. With Shrink Volume function, you can decrease an existing partition without reboot. Extend Volume helps you easily increase a partition size. However, many people try to shrink D drive, but found they cannot extend C drive, because Extend Volume is greyed out. In this page, I’ll tell why you cannot extend C drive in Windows Server 2012 (R2) Disk Management, and how to solve this problem in an easy way.
Scenarios of cannot extend C drive
The reason why so many people encountered this problem is because Extend Volume function disabled in most cases. Here I’ll show one by one.
Right-click Windows and click Disk Management.
1. Right click C drive directly, Extend Volume is grayed out.
2. Shrink the adjacent drive D and retry.
Shrink 10GB space.
Right click C drive, Extend Volume is still disabled.
3. Delete drive D and retry.
You cannot extend C drive, too.
4. Delete all volume in the Extended partition and retry.
Delete the Extended partition.
Now, Extend Volume becomes available.
As I said above, you cannot extend C drive in Windows Server 2012 in most cases.
Why cannot extend C drive in DM
There are 3 main reasons why you cannot extend C drive with Extend Volume function:
- You may use FAT32 file system. From Microsoft explanation, only NTFS and RAW format partition can be extended.
- There is no adjacent Unallocated space. Only when the Unallocated space is adjacent and at right side of C drive, you can expand C drive with the Unallocated space.
- You did not delete the adjacent Extended Partition. If the adjacent drive D is in the Extended Partition, you cannot extend C drive by simply deleting D. You should delete all volumes in the Extended Partition and then delete the entire Extended Partition.
Extend C drive without deleting
With 3rd-party server partition software, it is much easier to decrease and increase partition size. You can extend C drive without deleting. As long as there is free space in any other drives in the same disk, you can take free space out and add to C drive easily.
1. Download the application, right click the drive that has plenty of free space, and then select “Allocate Free Space”.
2. In the pop-up window, type the amount of free space to take out, and then select C drive in the drop-down box.
3. Press Apply on main window to proceed. As you see, C drive increased 15GB space.