By Cherry / Last Updated November 29, 2019

Many Windows Server 2016 users may find that the system partition is not enough to use and want to add unallocated space to extend system partition. Most of Windows users know that it is necessary to extend the system partition in case that it is running out of space, because that may lead the whole system and all the applications running slow. But how to add unallocated space for Windows Server 2016?

Fortunately, this article provides you many ways to add unallocated space for extending system partition.

Method 1. Using Disk Management

Windows Server 2016 still has the disk manage tool Disk Management. Click Start->Tools-> Computer Management -> Disk Management to open it, or you can press WIN+R and type “diskmgmt.msc” and press Enter to open it.

You can see the main environment of your disks. If there is an unallocated space behind the system partition, right click the system partition, select Extend Volume to add the unallocated space for Windows Server 2016.

DM Extend Volume

But, unfortunately, if there isn’t any unallocated space near to the system partition at its right side, the Extend Volume should be grayed out, and you cannot use the Disk Management to add unallocated space to Windows Server 2016.

Extend Volume Grayed Out

If you want to extend the system volume, you have to delete the partition behind C: partition and adjacent to C: partition (here should delete D: partition) first, which may lose your important data on the deleted partition.

Method 2. Using Diskpart

Diskpart is another utility of Windows for managing disks. Different with Disk Management, it uses syntax with command line. To extend system partition for Windows Server 2016, you can use the following syntax:

  • List disk

  • Select disk 0

  • List volume

  • Select volume

  • Extend size=

Take extending system partition on disk 0 as the following screen shot shows:

Diskpart Extend Volume

Thus, you will extend the system volume successfully. However, Diskpart can only extend volumes created on dynamic disks, not the volumes created on the basic disk that you have upgraded. If you want to extend a volume on basic disks, you will receive the error”Diskpart failed to extend the volume. Please make sure the volume is valid for extending.”

To extend a basic volume, it must be raw or formatted with NTFS file system and if there isn’t any unallocated space behind the partition, this command is invalid too. So, what should you do if those two methods cannot add the unallocated space for Windows Server 2016?

Add unallocated space for Windows Server 2016 with AOMEI Partition Assistant Server

As a Windows Server user, you must know that once the system partition ran out of space, the system will be running slower and slower, which could get a big damage for business. Thus, you may want to add much more unallocated space to the system partition of Windows Server 2016 in order to get more space to make the system running normally or even faster.

To get out of the restrictions of Windows Server 2016, here we highly recommend you AOMEI Partition Assistant Server, a great Windows disk manager for Windows Server 2019/2016/2012 (R2)/2008(R2)/2003, which can add unallocated space to extend system partition easily.

Step1. Download AOMEI Partition Assistant Server trail, install and launch it. You will see the main environment of your disks. And you can see the unallocated space is at the end of the disk. Right click C: partition, select Merge Partitions.

Merge Partitions

Step2. It will move to the page where you can merge the partition with the unallocated space even they are not near to each other.

Select Merge

Step3. Click OK, and you will back to the main interface, click Apply at the toolbar to submit all the operations. It will layout all the operations and you can confirm it, with no problem, click Proceed to go on, and wait till it finished.

That’s all. It is easy to add the unallocated space to Windows Server 2016. Actually, you can also use the Extend Partition Wizard to extend size for Windows Server 2016.