Make room for C

Make room for C drive on Windows PC and Server

This article introduces how to make space/room for system C drive partition on Windows 10/8/7/Vista/XP and Server 2019/2016/2012/2011/2008/2003 without data loss.

System C: drive running out of space is very common on both Windows PCs and servers, because many kinds of files are writing into it continuously. To fix this issue, the easiest and fastest way is increasing its partition size. Is it possible to make more room for C drive without starting over? Yes, of course, but there are several points you should know:

  1. Run reliable disk partition software, otherwise there is potential system and data damage risk.
  2. You can transfer free space inside other volumes to C drive, but no partitioning software can take free space from another separated disk.
  3. If there is no other partition, or no free space in all other partitions in the same disk, you can clone to another larger disk.
  4. If you use any hardware RAID arrays such as RAID 0, 1, 5, 10, do NOT break the RAID array or do any other operations in the RAID controller. It is the same with repartitioning physical disk drives.

Make room for C

Run reliable partition tool

When shrinking a volume to make room for C drive, the first and most important step is selecting a reliable partition tool. Some unreliable partitioning software is called as “data killer” by the people who experienced disaster. To reallocate disk partitions, the related parameters must be modified correctly, the files must be moved successfully, system info must be updated, too. Any slight error could cause system boot failure and/or data loss.

It costs a long time to recover even if you have backup, so be caution.

As the safest disk partition management tool, NIUBI Partition Editor provides innovative 1 Second Rollback technology to ensure system and data intact. If anything goes wrong while repartitioning hard drive, it automatically reverts the computer to original status in a flash like nothing happened.

Furthermore, it provides other technologies such as Virtual Mode, Cancel-at-will, Hot-Resize and advanced file-moving algorithm to help resize hard drives much more safer and faster.

2 ways to make space for C drive

If there is free space in any adjacent partition, you can combine it into C drive, then free space in drive D (for example) will be transferred to volume C. All files in D will be moved into a folder in C automatically. However, if you installed programs in D, it is not a good idea to combine C and D drive.

The best way to make room for C drive is by shrinking any other partition in the same disk. Everything keeps the same during this operation, you just need to drag and drop on the disk map.

Steps to make room/space on system C drive:

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

Resize volume

Drag the left border rightwards to shrink it, you may also enter an amount in the box behind Unallocated space before. (1024MB=1GB)

Shrink D

20GB free space is taken out of drive D and converted to Unallocated behind C drive.

Drive D shrank

Step 2 Right click C drive and select “Resize/Move Volume” again, drag the right border rightwards to combine the Unallocated space in the pop-up window.

Extend C

Click OK, system partition C is extended to 50GB, click Apply on top left to execute.

OS partition extended

Tip The pending operations (on bottom left) marked as Check can be done in Windows without rebooting.

If there is not enough free space in drive D, you can get from any nonadjacent partition, watch the video how to do this:


NIUBI Partition Editor can shrink allocated partition to make space for C drive, if the Unallocated space is adjacent on either side, simply combine into C drive. If it is nonadjacent, you just need to move it on either side of C drive and then combine. Besides shrinking, moving, extending, merging disk partitions, this disk partition software help you do many other operations.