How to Merge Unallocated Space with Primary C: Partition

DennisHPC said:

Hi folks. This is my first post on this forum, but I am a long-time Windows 10 user.

I just completed a fresh install of Windows 10 Pro (ver 22H2) on my desktop PC to a new Samsung 990 Pro (2 TB) NVme SSD. Everything is working fine, except for one minor issue. In Disk Management , I see the Primary C: partition, the EFI partition, and the Recovery partition. There is also an unallocated space/partition of 499 MB that is adjacent and to the left of the Primary C: partition. How can I merge this unallocated space with the Primary C: partition? I have tried using the free version of DiscGenius and Aomei software, but that function is not available or grayed out in that software. Thanks for your help.

The problem is almost certainly that the unallocated space to the left of the C partition is not actually adjacent to the C drive. I bet there is also the MicroSoft Reserved (MSR) hidden partition between them. Given this partition does not do any usefull, simplest option is to delete it, then you should be able to resize C partitioin to left using the tools you mentioned.

Minitool Partition Wizard Free will do it for sure.

Run following from an admin command prompt and post results to confirm my suspicion.

Code:

diskpart
list vol

If there is no MSR, you should be able to do what you require from Minitool Partition Wizard Free.

Same question at How to Merge Unallocated Partition with C: Primary Partition | Windows 10 Forums, same response fits here.

Pentagon said:

You can't use list vol for your purpose!
A Diskmanagement screenshot would help

A disk management screen will not tell you if there is a hidden msr partition.

You need to use diskpart but earlier I forgot - it is list par (not list vol) that is needed

Code:

diskpart
sel disk 0 (change if necessary to physical drive with C: partition)
list par

My pc shows


Once we see that we can tell if MSR partition is there, or in a position that would interfere expanding C drive using a partition tool.
As @SIW2 says, barely worth the effort recovering the space but in the end it is up to you - personally I would recover it as I like my partitions to be neat.