How to Extend C Drive in Windows Server 2019 Safely

by Andy, Updated on: July 30, 2022

When C: drive is getting full in Windows 2019 server, you can increase C drive space without recreating partitions and restore from backup. Nobody likes to do such time-consuming and boring work. To extend C drive in Windows Server 2019, you may try its native tool if you can delete the adjacent partition. The best way is resizing C drive without changing anything (except size), In this article I'll introduce how to extend C drive in Server 2019 with native tool and safe partition software.

Increase C drive space in Server 2019 with native tool

Windows Server 2019 native Disk Management utility has built-in Shrink Volume and Extend Volume functions to help change partition size. However, this native tool cannot extend C drive by shrinking D or other partition. Because "Extend Volume" only works when there's contiguous Unallocated space on the right. After shrinking D or any partition, Unallocated space is nonadjacent to C drive, so Extend Volume option is greyed out.

To extend C drive in Windows Server 2019 without any software, you must delete the adjacent partition D (or E). In addition, this adjacent partition must be Primary. After getting contiguous Unallocated space behind C drive, Extend Volume is enabled. With safe partition software, you can make Unallocated space on the left when shrinking partition, then C drive can be extended easily.

How to extend C: drive in Server 2019 with Disk Management:

  1. Move all files in the contiguous partition D: (E in some servers) to other place.
  2. Press Windows + X on your keyboard and click Disk Management in the list.
  3. Right click D: drive and select Delete Volume, then its disk space will be converted to "Unallocated".
  4. Right click C: drive and select Extend Volume, click Next till Finish in next windows.

Tips to extend system C drive in Server 2019 Disk Management:

  1. Unallocated space deleted from a partition must be next to C drive and on the same disk.
  2. If the contiguous partition D is Logical, its disk space will be changed to Free instead of Unallocated. In that case, the method above is invalid.
  3. It is not 100% safe. Pay more attention when there are both Primary and Logical partitions on a disk.

When resizing disk partition, all parameters of associated disk, partition and files must be modified correctly. Some software error and hardware issue such as power failure could cause part of the parameters failed to be modified. If it happens, system and/or data will be damaged. So make a backup in advance and run safe partition software.

Better than other disk partition tools, NIUBI Partition Editor is much safer and faster because of the advanced technologies:

With the help of its advanced file-moving algorithm, it is 30% to 300% faster to shrink, move and copy partition.

Extend C drive in Windows Server 2019 with safe software

In most of servers, there's free space in other partition on the same disk. You can shrink the one with plenty of free space, then part of free space will be changed to Unallocated. Finally add Unallocated space to C drive, then there will be more free space in C drive again. In this way, Operating System, programs and anything else keep the same with before. To accomplish this task, you just need to drag and drop on the disk map.

Download NIUBI Partition Editor and you'll see the main window with disk partition structure and other information on the main window. Available operations to selected disk or partition are listed on the left and by right clicking. Unavailable operations are hidden automatically to keep interface clean.

How to extend C drive in Windows Server 2019 without losing data:

  1. Right click the contiguous partition D (or E in some servers) and select "Resize/Move Volume". In the pop-up window, drag left border towards right or enter an amount in the box of Unallocated space before. Then drive D will be shrunk and Unallocated space will be made on the left of it.
  2. Right click C: drive and select "Resize/Move Volume" again, drag right border towards right to merge this Unallocated space, then C drive will be extended.
  3. Click Apply on top left to execute, done.
  4. Watch the video how to extend system C: drive in Server 2019:

Video Server 2019

  • If your right contiguous partition is E, simply replace D with E in the steps above.
  • If you want to shrink nonadjacent partition, there's an additional step to move Unallocated space before adding to C drive. (Method is shown in the video above).
  • NIUBI is designed to work in virtual mode first, real disk partitions won't be changed until click Apply to confirm. If you did anything wrong, simply click Undo to cancel.
  • The pending operations that are marked as Check can be done in Windows, the ones that are marked as Refresh requires rebooting to accomplish.
  • If C drive is on a RAID array, there's no difference to resize/extend RAID partition in Windows Server 2019. Don't break array or do any operations to RAID controller.

How to extend C drive partition with another disk

The size of a physical disk is fixed. You can change partition size but you cannot resize a disk. If there's only C drive or if all partitions on the system disk are almost full, no software can expand C drive by moving free space from another separate disk. If there's only C drive on the system disk, you can clone disk to a larger one and extend partition with extra disk space. Follow the steps in the video to extend C drive partition in Windows Server 2019 with a larger disk:

Video Server 2019

If there are other partition but no available free space on the system disk, another method is moving a partition to other disk. Then delete this partition and add its space to C drive. Learn how to move partition Server 2019.

Extend Server 2019 C drive in VMware/Hyper-V/Virtualbox

If you want to extend C drive in VMware/Hyper-V/Virtualbox, there's no difference when there's available free space on the same virtual disk. You just need to install NIUBI Partition Editor to the virtual machine and follow the steps in the first video above.

If the virtual system disk is almost full, you can expand it with VMware or Hyper-V. After expanding disk, additional space is shown as Unallocated at the end.

In Summary

To extend system C drive in Windows Server 2019, firstly check your disk partition structure and configuration, then follow the corresponding method above. NIUBI Partition Editor  can help you accomplish this task fast and safely. Besides shrinking and extending partition in Server 2019/2022 and previous Server 2003/2008/2012/2016, it helps do many other disk and partition management operations.