How to Extend System Partition in Windows Server 2012 R2

by James, Updated on: June 28, 2022

Comparing with data partitions, system partition C is very likely getting full after running the server for a period of time. Even if you installed all programs to anther volume, there are still large amount of junk files generated in system C: drive. If you contact support from server OEM manufacturers, they'll tell you to back up everything, delete and recreate all partitions, finally restore and verify data. If you do like that, your whole weekend may be wasted. Instead, you can resize/extend system partition in Windows 2012 server with safe tool. In this article, I'll introduce how to extend system partition in Windows Server 2012 R2 without losing data, fast and easily.

Tips before resize system partition in Server 2012 R2

1. Take care of system and data

Unlike data read-only programs such as file recovery software, partition manager software will modify disk partitions. Therefore, there is potential system damage and data loss risk, especially when you resizing system partition. It costs a long time to restore even if you have backup. So it is very important to use a safe tool.

Better than other tools, NIUBI Partition Editor has innovative technologies to protect your system an data.

It is 30% to 300% faster because of the advanced file-moving algorithm. This is very important when shrinking and moving a partition with large amount of files, especially when the operations require server reboot.

2. About hardware RAID arrays

Hardware RAID array has advanced abilities, it is realized by RAID controller with several disks. But to Operating System and NIUBI Partition Editor, there's no difference if you use SSD, HDD or any types of hardware RAID array. When extending system drive in Windows Server 2012 (R2), don't break RAID array or do any operations to the RAID controller, follow the same steps below.

3. Select corresponding solution according to your own partition layout

  1. In most of the servers, there is at least a data volume on the system disk, you just need to shrink it to get some Unallocated space and add into the C drive.
  2. If you want to shrink any non-adjacent partition to extend system drive, there's an additional step to move Unallocated space before adding to C drive.
  3. If there is no other partition or not enough free space on the system disk, no partitioning software can help you extend system partition by adding free space from another separate disk. In that case, you can clone system disk to a larger one and extend partition with additional disk space. If you don't want to copy whole disk, you can move a partition on the system disk to another one, then delete it and add the disk space to C drive.

How to extend system partition in Windows Server 2012 R2

Download NIUBI Partition Editor and you'll see all disks with partition layout on the right, available operations to selected disk or partition are listed on the left and by right clicking.

NIUBI Partition Editor

Extend system partition with contiguous volume

In most of servers, there's plenty of free space in the contiguous partition D (or E). In that case, shrink D and make Unallocated space on the left, and then add Unallocated space to C drive.

Steps to extend system partition in Server 2012 R2 with free space in D (adjacent volume):

  1. Right click D: drive and select "Resize/Move Volume", drag left border towards right in the pop-up window, or enter an amount in the box of Unallocated space before. Then part of free space in drive D will be changed to Unallocated on the left.
    Shrink D
  2. Right click system partition C: and select "Resize/Move Volume" again, drag right border towards right to combine this Unallocated space.
    Extend C
  3. Click Apply on the top left to take effect, done. (All operations before this step only work in virtual mode.)C drive extended

Extend system partition with nonadjacent volume

If there's insufficient free space in the contiguous partition D, you can shrink a nonadjacent partition on the same disk. Because D drive is in the middle, Unallocated space that shrunk from E is nonadjacent to C drive. You should move Unallocated space next to C drive in advance, otherwise, you cannot extend C drive.

How to extend system partition in Windows Server 2012 R2 with a nonadjacent volume:

  1. Right click drive E: and follow Steps 1 above to make Unallocated space on the left side.
  2. Right click drive D: and select "Resize/Move Volume", put the mouse pointer in the middle of D drive and drag towards right in the pop-up window. Then Unallocated space will be moved to the left.
  3. Right click system partition C: and use "Resize/Move Volume" to combine this Unallocated space.

How to extend system drive in Server 2012 R2 with NIUBI Partition Editor:

Video guide

Extend system partition with another disk

In few servers, there's only C drive on the same disk. In some servers, there's other volume on the same disk but there's no available free space. As I said above, you cannot add space from another separate disk with any software. In that case, you have 2 options:

1. Copy system disk to a larger one and expand partition with extra disk space:

Video guide

2. Move a volume to another disk, delete it and add its space to system C drive:

Video guide

Extend system volume for Server 2012 VM in VMware/Hyper-V

To save cost or because of other benefits, many companies run Windows Server 2012 as virtual machine. If you want to extend system partition in Server 2012 VM in VMware or Hyper-V, similarly, first check if there's available free space in any other volume on the same virtual disk. If yes, simply install NIUBI Partition Editor in the virtual machine and follow the steps in the video above.

If the entire virtual disk is full and there's no available free space, you can expand virtual disk in VMware/Hyper-V. After expanding disk, additional space will be shown as Unallocated at the end of original virtual disk, then you can extend system C drive with the additional Unallocated space.

In Summary

To extend system partition in Windows Server 2012/2016/2019/2022/2003/2008, you'd better back up first and run safe partition software. Because of the powerful data protection technologies, NIUBI Partition Editor helps you complete this task fast and safely. Follow the corresponding solution according to your own disk partition configuration. Besides shrinking, moving and extending partition, it helps you do many other disk partition management operations.