There are two main reasons why a hidden System Reserved Partition error can occur during a Windows 10 upgrade or update. When upgrading to or updating Windows 10, you would possibly encounter the error “We couldn’t update the system reserved partition,” error code 0xc1900104, or error code 0x800f0922. What are the first results of Windows 10 not updating the reserved system partition?
Reasons: The system reserved partition could not be updated
