We were upgrading part of our laptop fleet to Windows 11.

The Windows 11 Upgrade Verifier said we’d have no issues, yet we did.

The root cause of our upgrade problems was caused by:

  • Our laptop vendor writing font files to the System Reserve Partition (SRP)
  • The Windows 11 Upgrade Verifier does not detect the lack of needed free space.

The fix was to free up space on the SRP.
(Microsoft has also updated the Upgrade Verifier to detect the condition.)

“We couldn’t update system reserved partition” error installing Windows 10
Configure UEFI/GPT-Based Hard Drive Partitions