Microsoft clarifies about UNSUPPORTED_PROCESSOR” error on Windows 11 & Windows 10 PCs after August updates

Microsoft has sought to clarify about the “UNSUPPORTED_PROCESSOR” error faced by many Windows 10 and Windows 11 PC owners recently. This error was especially encountered by PC users updating to the latest Windows 11 update KB5029351 released on August 22.

According to the update posted by Microsoft on its official page, the error was not caused by the update KB5029351. Microsoft has blamed a limited subset of intel processors for causing this issue. It seems that some of the 13th Gen Intel Core Processors are facing “Performance Hybrid Architecture Blue Screen Hang” Issue with Windows.

Microsoft has also mentioned that the update KB5029351 may uninstall itself automatically. It has also recommended users to not reinstall KB5029351 if it gets uninstalled automatically. Read the full details of the issue and recommendations below.

Microsoft received reports about an “UNSUPPORTED_PROCESSOR” error

Status	Originating update	History
Resolved External	OS Build 22621.2215 KB5029351 2023-08-22	Last updated: 2023-09-07, 16:51 PT Opened: 2023-08-23, 19:44 PT

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. If this occurs, we recommend that you do not attempt to reinstall KB5029351.

Resolution: After investigating these reports, we have found that the “UNSUPPORTED_PROCESSOR” error was not caused by issues in KB5029351 and is limited to a specific subset of processors. For more information on this issue, please see 13th Gen Intel® Core™ Processor Families with Performance Hybrid Architecture Blue Screen Hang Issue with Windows* Preview Updates. This issue will not affect future monthly updates released for Windows. KB5029351 will not be offered to Windows devices that might be affected by this issue and it is recommended that you do not attempt to manually install it on affected devices.