Easy solution of cannot extend volume C in Disk Management

From Windows Vista, you can shrink and extend a volume under Disk Management snap-in. It is a big improvement that enables you to resize partitioned drive to a certain extent. However, Windows Disk Management still cannot solve most of disk space issue, the typical example is that you cannot extend C drive by shrinking other one. Many people feedback Extend Volume is greyed out when extending C drive. In this article I’ll explain why you cannot expand C drive with Extend Volume function and show you easy method to fix this issue. This method is valid in Windows 10/8/7/Vista and Server 2016/2012/2011/2008 (R2).

Disk Management won’t let me extend C drive

The space of a hard disk cannot be increased, so to extend a drive, you must delete or shrink another one to release free space at first. Some people do not know about this and open Disk Management to run Extend Volume directly, of course you cannot extend C drive.

To most of the Windows computer users, the annoying problem is that they still cannot expand C drive after shrinking D.

Right click drive D and select Shrink Volume:

Enter the amount of space to shrink:

As you see, Windows won’t let me extend C drive, because Extend Volume is still disabled.

From Microsoft explanation, there should be adjacent Unallocated space, so is it possible to expand C drive by deleting D? (Note: don’t do this, the steps below are just used to show you the reasons)

Right click D and select Delete Volume:

Unfortunately, I cannot extend C drive again, bad experience, right?

Have you noticed that the space deleting from D is Free instead of Unallocated? In addition, it is inside of Extended partition together with drive E. Search by Google, to convert the Free space to Unallocated, I should delete all volumes in the Extended partition.

Let’s see what happens, right click E and select Delete Volume:

Check again, Disk Management still won’t let me extend C drive.

Okay, continue deleting the entire Extend partition:

Finally, Extend Volume function is available:

It is really troublesome to extend C drive in Disk Management.

Why can’t extend volume in Windows server and PC

The GUI and functionalities are absolutely the same in Windows 7, 8, 10 and Server 2008, 2012, 2016, so you may encounter the same problem in these Operating System. Luckily, if you use Server 2016 or Windows 10, there is less change to see the issue caused by Logical and Extended partition, because GPT partition is used as default when installing.

Summary – what cause you unable to extend C drive in Disk Management:

1. FAT32/16 partition cannot be extended, only NTFS or RAW partition is valid.
2. Only when there is adjacent Unallocated space on the right side, you can extend a volume.
3. If the adjacent volume D is Logical partition, you have to delete it and all other volumes in the Extended partition.

What to do when cannot extend volume C in DM

Actually, it is very easy to solve this problem if you have shrank D. Just move the Unallocated space to behind C drive with partition software and then Extend Volume will be available.

Let’s back to the status after shrinking D.

Download NIUBI Partition Editor, right click volume D and select “Resize/Move Volume”:

Drag the middle position rightwards to move it:

Now the Unallocated space is behind C drive. You may either extend C drive in Disk Management or with this free partition software.

If you have not shrank D or other volume, I suggest you run the partition software directly, because it is much easier.

Follow the steps in the video:

NIUBI Partition Editor is the safest partition software to resize/move disk partitions. The unique 1 Second Rollback technology can ensure 100% data safe, which is very important for both Windows Server and PC. It provides basic partition management to create, delete, format partition, change drive letter, etc. Advanced management to resize/move existing partition without data loss, copy, hide, set active, convert, defrag, check partition and much more.