MSI has officially confirmed the recent surge of blue screens of death (BSODs) encountered by Windows users after installing this week's optional preview updates is linked to some of its motherboard models. 

"MSI has received several reports of users encountering a Blue Screen of Death that has an error message that reads 'UNSUPPORTED_PROCESSOR' with MSI's 600/700 series motherboards after installing the Windows 11 update, KB5029351 Preview," the company said. 

"Both MSI and Microsoft are aware of the 'UNSUPPORTED_PROCESSOR' error and have begun investigating the root cause."

The Taiwanese PC vendor has also advised all users to avoid installing the August 2023 preview updates on Windows systems for now.

Those who have already updated their systems and have been impacted by the blue screens should revert their BIOS to a previous version and uninstall the optional Windows updates.

MSI provides detailed information in this video on using M-FLASH to revert to previous BIOS versions on MSI motherboards.

Microsoft also acknowledged this known issue on Wednesday, saying that the affected platforms include Windows 10 21H2/22H2 and Windows 11 22H2. 

"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 2," the company said.

Redmond added that the buggy optional updates "might automatically uninstall to allow Windows to start up as expected."

This was confirmed by multiple customers [1, 2] who said the problematic updates were rolled back automatically after several system reboots.

Microsoft asked impacted users who have encountered the BSOD issues to file a report using the Feedback Hub.

This week, Microsoft also introduced a new Windows 11 policy granting admins improved control over the delivery of monthly non-security preview updates on enterprise devices.

Upon activation, users can choose between automatically installing optional updates or manually selecting the updates they wish to install.