Microsoft Acknowledges New “Unsupported Processor” BSOD Errors on Windows 11


Key takeaways:

  • Microsoft’s optional update, KB5029351 can trigger ‘Blue Screen of Death’ (BSOD) errors with an “UNSUPPORTED_PROCESSOR” message for some users
  • Users, particularly those with MSI motherboards, reported encountering the BSOD issue on Windows 10 versions 22H2 and Windows 11 versions 21H2 and 22H2.
  • Microsoft has initiated an investigation into the matter, urging affected users to provide error reports to assist in identifying the root cause.

Microsoft’s latest optional update for Windows 11 version 22H2, KB5029351, designed to bring improved features and experiences, has instead left some users staring at the familiar ‘Blue Screen of Death’ (BSOD) accompanied by an ‘UNSUPPORTED_PROCESSOR’ error message. The company acknowledged the issue on the Windows Health Dashboard yesterday.

“Microsoft has received reports of an issue in which users are receiving an “UNSUPPORTED_PROCESSOR” error message on a blue screen after installing updates released on August 22, 2023 ( KB5029351) and then restarting their device. KB5029351 might automatically uninstall to allow Windows to start up as expected,” Microsoft explained.

In a Reddit thread, several users reported that the BSOD issue seems to specifically affect PCs with some MSI motherboards, particularly when the latest BIOS updates have been installed. Microsoft confirmed that the problem not only impacts Windows 11 version 22H2, but the version 21H2 of the OS and Windows 10 version 22H2 as well.

Microsoft released these optional preview updates for Windows 11 and Windows 10 on August 22. On Windows 11 version 22H2, the company introduced a new “Enable optional updates” policy that lets IT admins configure monthly, optional cumulative updates and Controlled Feature Rollouts (CFRs). The update also brings some minor improvements such as a new app defaults behavior and a new hover behavior on the Search box.

Microsoft asks Windows 11 users to file a report about BSOD errors

Microsoft is currently investigating the issue to determine the root cause. Meanwhile, the company is asking affected users to try to reproduce the problem and share details and a recording of their screens via Feedback Hub.

Last month, Microsoft blamed third-party apps for breaking the Start menu in Windows 11. The problem affected users who have installed these apps to customize their Windows installation. At the time, Microsoft advised users to uninstall the third-party apps or contact the developer to roll out a fix.