Windows 11 Has Stopped Working on Older CPUs

However, some of those older PCs can no longer use Windows 11 due to a CPU instruction update.

Microsoft started testing Windows 11 builds back in February that required the POPCNT CPU instruction for some system functions.

Instead, Windows 11 gets stuck in a reboot loop.

Microsoft declined to comment on the change when asked byThe Register.

The POPCNT CPU instruction is part of the SSE4.2 instruction set.

Theres no workaround for missing CPU instructions.

This change only affects people who bypassed those official requirements on computers with incredibly old processors.

However, some applications and games dont work without that CPU instruction either,such as Apex Legends.

Source: Bob Pony on Twitter/X (1,2),The Register