The impending release of Windows 11 24H2 has raised concerns for users with older computers, as the latest version poses compatibility challenges. Upon installation on aging PCs, this update triggers a hard stop, preventing the operating system from loading. The root cause lies in the utilization of processor machine instructions that older processors lack.
Twitter Discovery:
A Twitter user known as TheBobPony has highlighted a significant hurdle for computers dating back to the last decade. Commencing with build 25905, Windows 11 version 24H2 introduced the use of the POPCNT instruction, absent in older processors. Multiple system files, ranging from the Windows 11 kernel to USB XHCI drivers, now rely on the POPCNT guide, notes NIX Solutions. Consequently, computers lacking support for this instruction simply fail to boot.
Uncertain Rationale:
The rationale behind Microsoft’s insistence on the POPCNT instruction remains unclear. Introduced in 2008 as part of the Nehalem architecture, this instruction initially appeared in contemporary AMD processors of that era. Intel Core processors adopted the POPCNT instruction in the second-generation Core chip, Sandy Bridge, released in 2011. Despite the evolution to Intel’s 14th-generation Core chips this year, it seems that even moderately aged hardware should possess POPCNT support.