While upgrading to Windows 11, upgrading to Windows 10, or while updating to a newer version of Windows 10, you may encounter the “We Couldn’t Update the System Reserved Partition” error with Windows Update, the creation tool or with the update wizard. These errors can also be accompanied by the error code 0xc1900104 or 0x800f0922.
In this tutorial, we are going to see how to resolve this “Unable to update the system reserved partition” error in order to continue and successfully update to Windows 11 or Windows 10 operating system.
The System Reserved partition
The System Reserved Partition (SRP) is a small partition on your computer’s hard drive / SSD that stores boot information for Windows. Some anti-virus and security applications may write and fill this System Reserved partition. When there is not enough free space in this partition, Windows updates may fail, accompanied by the error message “Unable to update the system reserved partition”.
To resolve the issue, 15MB of space should be freed on the System Reserved partition when upgrading from Windows 10 to Windows 11 or upgrading from Windows 7 or 8.1 to Windows 10; and 13MB of space if you are updating Windows 11 or 10 to a newer version. Microsoft recommends that you delete the Fonts folder that contains fonts to free up disk space.
“We Couldn’t Update the System Reserved Partition” Error Fix on Windows 11 or 10
Step 1: Determine if the disk is in MBR or GPT
To get started, determine if your disk is in MBR or GPT format. If your disk is in GPT format, Windows is installed in UEFI mode; if the disk is in MBR format, Windows is installed in BIOS mode.
Step 2: Free up space on the system reserved partition
Windows UEFI + GPT disk
- If you have a GPT disk, follow these instructions:
- Open a command prompt as an administrator.
- Mount the system reserved partition and assign it the drive letter Y:
mountvol y: /s - Switch to drive Y:
y: - Enter the Fonts folder:
cd EFI\Microsoft\Boot\Fonts - Delete all files (confirm deletion):
del *.* - Re-upgrade to Windows 11 or Windows 10.
Windows BIOS + MBR disk
If you have an MBR disk, follow these instructions:
- Open the Disk Management tool
- Right-click on the System Reserved partition> Change drive letter and paths > Add > choose Y as the drive letter> OK.
- Open a command prompt as an administrator.
- Switch to drive Y:
y: - Enter the Fonts folder:
cd Boot\Fonts - Recover file access:
takeown /f . /r /d o - Save the current permissions:
icacls y:\* /save %systemdrive%\NTFSp.txt /c /t - Display the name of your user account:
whoami - Give access rights to your user account:
icacls . /grant “<nom du compte utilisateur>”:f /t - Delete all files (confirm deletion):
del *.* - Restore permissions:
icacls y:\ /restore %systemdrive%\NTFSp.txt /c /t
icacls . /grant system:f /t
icacls Y: /setowner “SYSTEM” /t /c - Return to the Disk Management tool and delete the drive letter for the System Reserved partition.
- Re-upgrade to Windows 11 or Windows 10.
great, thanx