By Michael / Last Updated June 27, 2021

What is the System Reserved partition?

System users may inquire about the 128MB partition that is created along with the 100MB system partition during the installation of Windows. This is known as Microsoft Reserved Partition or MSR.

A Microsoft Reserved Partition is only created when a drive formatted in a Globally Unique Identifier or GUID partition table (GPT) format and when the BIOS is set for Unified Extensible Firmware Interface (UEFI). Drives less than 16 GB will have a 32 MB MSR, and drives larger than 16 GB will have a 128 MB MSR. MSR partition is invisible in Disk Management and users cannot save or delete data on MSR partition.

During the installation of Windows 8, the system will automatically be divided into 3 partitions, partition 1, partition 2, and partition 3 respectively. The 300MB is Recovery partition, 100MB System partition, and 128 System Reserved partition.

How to manually create System Reserved partition?

To create Microsoft System Reserved partition, you can enter into WinPE and create it manually. Here are the detailed steps.

Step 1. Boot the computer from the installation disc and press any key to continue.

Step 2. Click Install, and set language and other preference. Then click Next.

Step 3. Open the command prompt by pressing Shift + F10.

Step 4. Type the following command and press Enter after each command.

● diskpart
● list disk
● select disk 0

Step 5. If your disk is MBR style, you need to convert it to GPT using the following command.

● clean
● convert gpt

Step 6. Then use the following command to create System Reserved partition.

● create partition msr size=128
● create partition efi size=300
● create partition primary size=40960
● exit

Create System Reserved Partition

Step 7. Then go back to the Install Windows page, refresh the page and select the 40GB to install.

How to deal with Extra Recovery partition?

After converting MBR to GPT, the system will distribute an extra Recovery partition with about 500MB. This partition is hidden and you cannot find it in Windows File Explorer. Some users would like to delete it to free up more space. However, you cannot delete it by Disk Management because it is protected by system. You have to turn to a professional tool.

AOMEI Partition Assistant is a free disk manager which can help you to create, resize, extend, hide, delete, format partition. With this tool, you can manage your reserved partition and other disk partitions easily. 

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1. Delete GPT reserved partition

Step 1. Download AOMEI Partition Assistant and launch the software.

Step 2. Right click the Recovery partition that you want to delete and select Delete Partition.

Delete Recovery Partition

Step 3. Select a way to delete partition. It is recommended to choose Delete partition quickly. Then click OK.

Delete Partition Quickly

Step 4. Click Apply to submit the change.

Proceed Delete Recovery Partition

2. Increase System Reserved partition

When you upgrade to Windows 10 from Windows 8.1 or Windows 7, the upgrade may fail with the following error message: "We couldn't update the system reserved partition". This error is usually caused by insufficient space on the System Reserved partition. In this case, you should increase the size of System Reserved partition.

Step 1. Right click on a redundant partition and select "Resize Partition" to generate unallocated space.

Resize D

Step 2. In the pop-out "Move and Resize Partition" window, tick the box: "I need to move this partition" and drag the slider bar from left to right. You can also enter the specific amount of space you want to shrink. After that, click OK.

Shrink D

Step 3. You can see here is unallocated space after System Reserved partition and before the C: drive. Right click System Reserved partition and select "Resize Partition".

Resize C

Step 4. In the pop-out window, drag the slider bar rightward to extend System Reserved into unallocated space.

Move C

Step 7. To extend the reserved partition, Right-click on it again, and select "Resize Partition".

Resize System Reserved Partition

Step 8. Extend the partition with dragging the border. And click "OK".


Step 9. Click "Apply" on the main interface to commit all changes.



In this article, you have learned what GPT Reserved partition 128GB is and how to deal with the extra Recovery partition and how to increase System Reserved partition. With AOMEI Partition Assistant, you can easily manage your disk. And AOMEI Partition has many other features. For example, you can move GPT Reserved partition. If you accidentally delete EFI partition, you can use Partition Recovery Wizard to get it back. Besides, after Windows install, if you are not satisfied with size of hard drive, you can repartition the hard drive without efforts.