Windows 11 update KB5029351 causes BSOD ‘unsupported processor’ error

Microsoft confirms BSOD with a "UNSUPPORTED_PROCESSOR" error in the latest update for Windows 11 and 10.

Windows 11 update settings
Windows 11 update settings
  • Microsoft confirms Blue Screen of Death error with the latest update of Windows 11.
  • The problem is also affecting Windows 10 devices.
  • The error shows the “UNSUPPORTED_PROCESSOR” message on supported processors.
  • The update may need to be uninstalled manually to boot the device correctly.

UPDATED 9/6/2023: The update KB5029351 for Windows 11 (released as the August 2023 update) is causing a Blue Screen of Death (BSOD) with a “UNSUPPORTED_PROCESSOR” error on devices with supported processors. Microsoft is aware of the issue and it’s investigating the problem. The company also notes that the issue extends to Windows 10 after installing the update KB5029331.

Since this appears to be an unknown issue, as part of the investigation, the company is asking users to report the problem through the Feedback Hub app.

While the root of the problem is still unknown, it seems that this bug is mainly affecting motherboards from MSI from Intel’s 600 series (Z690) and 700 series (Z790). The company will provide “an update when more information is available.”

Microsoft also says the update may uninstall automatically if the computer keeps crashing with the BSOD errors to allow it to start normally. If this is not the case, you may need to boot the computer in the Windows Recovery Environment (WinRE) to uninstall the KB5029351 update on Windows 11. On Windows 10, you will have to use these instructions.

Update August 28, 2023: According to an update from Microsoft, the “UNSUPPORTED_PROCESSOR” error was not caused by issues in KB5029351 and is limited to a specific subset of processors. Although the company isn’t sharing any specific details of the root of the cause, it is working with device manufacturers to resolve the issue. At the time of this writing, the company is mitigating the issue by temporarily halting the rollout of KB5029351 on devices that encounter problems. If you have any issues, Microsoft recommends contacting the processor manufacturer.

Update September 6, 2023: MSI has released firmware updates for its motherboards to resolve the UNSUPPORTED_PROCESSOR error code. According to the company, the problem occurred as a result of a specific Intel Hybrid Architecture firmware setting on devices with 13th-Gen Core i9 processors. Furthermore, the motherboard manufacturer says that the issue appears on computers running the latest update of Windows 10 and 11.

About the author

Mauro Huculak is a Windows How-To Expert who started Pureinfotech in 2010 as an independent online publication. He has also been a Windows Central contributor for nearly a decade. Mauro has over 14 years of experience writing comprehensive guides and creating professional videos about Windows and software, including Android and Linux. Before becoming a technology writer, he was an IT administrator for seven years. In total, Mauro has over 20 years of combined experience in technology. Throughout his career, he achieved different professional certifications from Microsoft (MSCA), Cisco (CCNP), VMware (VCP), and CompTIA (A+ and Network+), and he has been recognized as a Microsoft MVP for many years. You can follow him on X (Twitter), YouTube, LinkedIn and Email him at [email protected].