Increase C drive space

Increase C drive space/size on Windows Server 2016

It is very common that C drive running out of space in both Windows server and PC. If there is unused space in other partitions of the same disk, you can increase C drive partition size without wasting a long time to back up and restore. This article shows how to increase C drive space on Windows Server 2016 safely and easily.

Increase C drive partition with software

Windows Server 2016 native Disk Management provides advanced Shrink and Extend Volume functionalities to change partition size, but Extend Volume can only help increase C drive partition size when there is adjacent Unallocated space on the right side, so it is useless in most cases. To increase C: drive space on Windows Server 2016, disk partitioning software is better choice.

However, NOT every partition software can accomplish this task well. There is system and data damage risk when you change size of allocated partitions, because all parameters of disk, partition and files should be modified correctly, furthermore, all files in the drive that you want to shrink should be moved to new locations. Any software error or hardware issue could cause system boot failure, partition and files corruption.


Better than other tools, NIUBI Partition Editor is integrated innovative 1 Second Rollback technology. If anything goes wrong during re-partitioning disk drives, it automatically reverts the server to original status in a flash. In that case, everything keeps the same like nothing happened. Backup software can help you restore if disaster occur, but it costs a long time to restore and verify data. Data safety and keeping online are most important to a server.

To increase C drive size on Server 2016, you may either merge or shrink another partition, all that you need to do is dragging and dropping on the disk map.

Option 1 Increase C drive size by merging other partition

All disk partition software can only merge two adjacent partitions, that means merge drive D into C. By doing this, all files in D will be moved into C drive and unused space will be transferred into C drive.

Caution If there are programs installed or some Windows services running from D drive, do NOT use this option. You’d better shrink D to expand C drive, so you won’t lose partition D and everything keeps the same.

How to increase C drive by merging D on Server 2016:

Step 1 DownloadNIUBI Partition Editor, right click drive D or C and select Merge Volume.

Merge volume

Step 2 Click the check-box in front of both drive D and C, and then click the drop-down box on bottom to select C: as destination drive.

Select drives

Click OK and back to the main window, where you’ll see that drive D is merged into C. There is a pending operation “Merge volume D: to C:” added on bottom left. To confirm this operation, click “Apply” on top left to execute.

Merge complete

Tip All files in partition D will be moved to a folder in C drive named as “D to C (date and time)” automatically.

Option 2 Increase C drive space by shrinking other partition

As I said above, by shrinking partition D, part of unused space in it will be converted to Unallocated, which can be added into C drive easily. In this way, no partition deleted and everything keeps exactly the same after re-partitioning, so this option is better.

Steps to increase C drive on Server 2016 by shrinking D:

Step 1 Run NIUBI Partition Editor, right click drive D and select “Resize/Move Volume“.

Resize Volume

Drag the left border rightwards in the pop-up window to shrink it.

Shrink D

20GB unused space is converted to Unallocated on the left side of D.

Drive D shrank

Step 2 Right click drive C and select “Resize/Move Volume” again. Drag the right border rightwards to hold the Unallocated space.

Extend C drive

Click OK, C drive size is increased to 50GB.

Extend partition C

Remember to click Apply on top left to execute.

In Summary

To increase C drive space/partition size on Windows Server 2016, you’d better select the safe partition software, otherwise, there is system/data damage risk, or wast a long time to restore. NIUBI Partition Editor can help you accomplish this task safely and easily. When there is no programs or Windows services in drive D, you may increase C drive size by merging D, otherwise, it’s better to shrink D.

Tip If there is not plenty of free space in the adjacent drive D, you can increase C partition by getting free space from any other partition in the same disk. To do this, you just need additional step to move Unallocated space. Watch the video: