I'm trying to install a Windows 10 update, but I'm getting an error that as far as I can tell is because my system partition is full. So I'm going into a partition manager, and as far as I can tell I need unallocated space near the system partition in order to expand it. I want to take space from my C: drive, but the problem is that I can only seem to create unallocated space right next to the C: drive and between the C: Drive and the EFI System Partition, there is a 128 MB Reserved Partition that I can't figure out how to move, or extend, or merge, do anything to at all.

So how do I extend the System Partition when I can't seem to do anything to the Reserved Partition and it is in the way?

This is a screenshot of what I'm looking at on my partition manager:


  • DO NOT delete that 128MB partition if you want your system to boot. – Ramhound May 30 '17 at 23:15
  • The solution would be to create images of each required partition to boot your system, apply those images to a new disk, then finally rebuild your bcd to point to new Windows partition. I strongly suggest have somebody who knows more about partitions do this for you. It's not for the fate of heart or the inexperienced – Ramhound May 30 '17 at 23:21
  • You should use another tool like gparted or pmagic. They are both ISO you boot from. Shrink your C: drive. Then move it forward. Then move any other parfition forward. When the free space is in front of the drive you want to make bigger resize, and expand that partition to consume the free space. – cybernard May 30 '17 at 23:28

Your system partition (C drive) has 130+GB free, you don't need to do anything. If you don't know what you are doing when it comes to the partitioning, you can really screw up your Windows installation. Even if you could resize the partition you are talking about, 1. It's tiny, only 128MB, and 2. Windows needs it to properly work.


Your system has UEFI firmware interface and Hard Disk Drive has GPT partition table.

  • Partition with System label, 100 MB capacity and fat32 file system is EFI system partition (ESP). When a PC is booted, UEFI loads files stored on the ESP to start OS. ESP contains the boot loaders/kernel images for OS.

EFI system parition

  • Partition with no label, 128MB capacity and no file system is Microsoft Reserved Partition (MSR). GPT disks and the UEFI do not allow hidden sectors. MS reserves a disk space using MSR providing an alternative data storage space.

Microsoft Reserved Partition

Never Delete/Format Reserved Partition or System Partition

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