Hi,

I have a specific technical question about SBAT that I could not find addressed anywhere in public documentation, forums, or Microsoft's own tooling.

My system (MSI MPG Z590 Gaming Plus, Intel i7-11700K, Intel PTT TPM 2.0, Windows 11 Pro 25H2) has been logging Event ID 1796 with UpdateType: SBAT on every boot since the March 2026 out-of-band update introduced the SBAT update attempt. HResult: -2147024895 (0x80070001 — ERROR_INCORRECT_FUNCTION).

The system is otherwise fully compliant:

- UEFICA2023Status: Updated

- WindowsUEFICA2023Capable: 2 (2023 cert in DB, booting from 2023 signed boot manager)

- AvailableUpdates: 0x0400 (only SBAT bit remains, stuck)

- SBAT\UpdateStatus: 2

- Secure Boot enabled throughout, never disabled

- No manual registry or certificate modifications — everything was applied via standard Windows Update and an OEM BIOS update provided by MSI

Two things I cannot find explained anywhere:

1. Every documented case of a failing SBAT update shows HResult 0x800700c1. My system returns 0x80070001. These are different error codes — 0x80070001 is ERROR_INCORRECT_FUNCTION, not ERROR_BAD_EXE_FORMAT. I cannot find any public documentation, tool, or forum post that addresses 0x80070001 specifically in the context of a SbatLevel write attempt. What does this code indicate at the firmware level?

2. SbatLevel is a Boot Services variable. The write attempt happens during boot. On this specific platform (Z590 + Intel PTT), the write has been failing consistently across multiple BIOS versions and multiple clean Windows installations. Is there a known class of firmware implementations on this generation of Intel platform that cannot support the SbatLevel write, and if so, is this an expected/documented limitation or a gap that needs addressing before June 2026?

I am not looking for a workaround. The system is functional and secure. I am looking for a technical explanation of what this specific error code means in this specific context, because it does not appear in any public resource I can find.

Thank you.