How to add space to C drive on Windows Server 2012 R2

When C drive is getting full in Windows 2012 server, nobody likes to start over. It can't be better if you can add more space to C drive without losing programs and data. However, there's potential data loss risk while resizing server partition, so you'd better back up first and run reliable partition tool. This article gives detailed steps to add space to C drive in Windows Server 2012 R2 with inbuilt Disk Management and the safest partition software.

Content:

Add disk space to C drive without software
Add space to C drive from D in Server 2012 R2
Add free space to C drive from nonadjacent partition
Add more space to C drive in VMware/Hyper-V

Add space 2012

Add disk space to C drive without software

Windows Server 2012 Disk Management has "Shrink Volume" and "Extend Volume" functions to change partition size without losing data in most cases. Many server administrators try to shrink D and extend C drive but failed, because "Extend Volume" is grayed out.

As you see in my server, I got 18.96GB unallocated space after shrinking drive D, but Extend Volume is disabled for both C: and E: drive.

This is because:

Unallocated space can only be made on the right side while shrinking a partition via "Shrink Volume" function in Disk Management.
Extend Volume can only combine unallocated space to the adjacent partition on the left.

After shrinking D drive, C drive is non adjacent and E: is on the right of the unallocated space, so Extend Volume doesn't work for them.

If you don't want to use any software, the only way to add disk space to C drive is by deleting the adjacent partition D.

How to add more space to C drive in Windows Server 2012 R2 via Disk Management:

Back up or transfer all files in the right contiguous partition (D:).
Press Windows and X together on the keyboard, click Disk Management from the list.
Right click drive D: and select "Delete Volume". (Don't do this if you installed programs or any Windows services in it.)
Right click system C: drive and select "Extend Volume".
Simply click "Next" button till "Finish" in the pop-up dialog box.

If the right adjacent partition is logical, you still cannot extend C drive after deleting D.

Add space to C drive from D (adjacent volume)

There are many server partition software in the market but few are safe enough. Some unreliable software could cause system damage and data loss. If it happens, you have to start from scratch or waste a long time to restore everything.

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

Virtual Mode - all operations will be listed as pending for preview, real disk partitions won't be changed until click "Apply" to confirm.
Cancel-at-will - if you applied wrong operations, you can cancel the ongoing operations without damaging partitions.
1-Second Rollback - if it detects error while repartition hard drive, it automatically reverts server to original status in a flash.
Hot Clone - clone disk partition as backup without server interruption, you can boot from the clone disk immediately if system disk goes wrong.

It is 30% to 300% faster because of the advanced file-moving algorithm. This is very helpful to save time.

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

How to add space to C drive from D on Windows Server 2012 (R2):

Right click D: drive and select "Resize/Move Volume", drag the 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 will be converted to unallocated on the left.
Right click C: drive and select "Resize/Move Volume" again, drag the right border towards right to combine this unallocated space.
Click Apply on top left to execute, done. (All operations before this step only work in virtual mode.)

Add free space to C drive from nonadjacent partition

If there is not enough free space in the adjacent drive D, you can shrink E or other non-adjacent partition on the same disk. In that case, there's an additional step to move partition D to the right.

Right click drive E: and follow Steps 1 above to make unallocated space on the left side.
Right click drive D: and select "Resize/Move Volume", drag the middle of it towards right in the pop-up window. Then D drive will be moved to the right and unallocated space will be moved to the left at the same time.
Right click C: drive and follow Step 3 above to add unallocated space to C drive.

How to add space to C drive in Server 2012 R2:

If there's no available free space in other volumes on the same disk, no software can add space to C drive from other separate disk. In that case, follow the steps to copy disk to a larger one and add extra disk space to C drive.

Increase C drive space in VMware/Hyper-V

If you run Windows Server 2012 as guest virtual machine in VMware or Hyper-V, firstly, check if you can shrink any data volume to get unallocated space on the same virtual disk. If yes, there's no difference.

If there's no available free space, you can increase disk size without copying to other one, follow the guide below:

After expanding disk, additional disk space will be shown as unallocated at the end of original virtual disk. Follow the method in the video and combine unallocated space to C drive.

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