Microsoft, but mostly AMD, silent on Windows 11 TPM Attestation bug even on supported Ryzen

windows 11 tpm

Last week, preliminary system requirements for Windows 12 purportedly surfaced. While there wasn't much to go on, we did get more direct clues as to what Windows 12 may eventually resemble, and also learned about Microsoft's supposed plans for a stripped down, AI-powered Windows 12 "CorePC" implementation.

Neowin forums are generally buzzing with Microsoft and Windows enthusiasts, and the comment section on the Windows 12 system requirements article saw some enthused but healthy discussion. One of the comments by a long-time Neowin forum member RejZoR caught my attention, which stated that TPM Attestation on their new AMD Ryzen 7 5800X3D system was broken, even though it worked perfectly fine with their previous 5800X processor. The issue is slightly reminiscent of another bug where Windows Security fails to detect the TPM even when the security chip is present.

When I looked around the internet, it indeed looked like a fairly common issue, with plenty of forum posts online talking about the same problem on the Ryzen 7 5800X3D. And while there are also some mentions of other AMD Ryzen CPUs, as well as some Intel chips, it seems the 5800X3D is by far the most affected part. This is pretty bizarre as AMD's 5800X3D should have no problems with TPM attestation as it comes with TPM version 2.0.

Here's the status of TPM attestation on my own Ryzen 7 5700G, which shows as "Ready":

TPM attestation on my Ryzen 7 5700G — On my Ryzen 7 5700G personal rig

Perhaps Microsoft may be aware of the bug as the known issues list, at least for Windows Autopilot, notes that TPM attestation for AMD may fail with an error code "0x80070490". The issue says:

TPM attestation for AMD platforms with ASP firmware TPM may fail with error code 0x80070490 on Windows 10 and Windows 11 systems. There's currently no update available to resolve this issue.

However, sadly, as the note says above, there is no resolution for this issue. Meanwhile, AMD also does not seem to have any solution for the bug. There are a lot of unanswered forums online where TPM attestation would apparently no longer work after a CPU change or upgrade. The only way around the issue it seems is to purchase a standalone TPM module, and that requires a TPM header which isn't available on all boards.

Source: Neowin forum via AMD, Microsoft forums (1) , (2) , (3) , (4)