“We couldn’t update system reserved partition” error installing Windows 10

Applies to: Windows 10

Symptoms


When upgrading to, or updating, Windows 10, you might encounter the error “We couldn’t update system reserved partition”, error code 0xc1900104, or error code 0x800f0922. 

Cause


The System Reserved Partition (SRP) may be full. The System Reserve Partition (SRP) is a small partition on your hard drive that stores boot information for Windows. Some third-party anti-virus and security apps write to the SRP, and can fill it up.

Resolution


Caution: these steps are complicated, and carry some risk. This is best done by advanced users with experience using the command line. If you make an error in entering these commands, you could put your device in a no-boot situation, and possibly lose data you have stored on the device.

To upgrade your device, you'll need to free up 15MB of space on the SRP using the appropriate method below, and then try the upgrade again. If you're updating Windows 10, you need to free up 13MB.

First, determine whether the SRP is GPT or MBR partition style:
 
  1. Press the Windows key + R. In the Run window that comes up, type diskmgmt.msc and press Enter.
  2. Press-and-hold or right-click on the Disk (such as Disk 0) that contains the SRP, and select Properties.
    Properties
  3. Choose the Volumes tab.
  4. The Partition Style: line will say either GUID Partition Table (GPT) or Master Boot Record (MBR).


Second, choose which method you need: