UNSUPPORTED_PROCESSOR BSOD on MSI motherboards

This preview update decided that Intel 12th and 13th Gen CPUs on MSI 600/700 series motherboards were “unsupported processors.” Immediately after installing, systems hit an UNSUPPORTED_PROCESSOR BSOD on boot — no login screen, no Safe Mode option, just a blue screen declaring your processor unsupported. On hardware that was, of course, fully supported. MSI had to publish a public warning telling users not to install the update. The conflict was between Windows’ CPU verification and Intel microcode that MSI had embedded in recent BIOS updates. Microsoft blamed the OEM. The OEM blamed Microsoft. Users blamed both.