
If your PC has a Nehalem-based Core i7 processor from 2008 or earlier, it can no longer run Windows 11 after the next scheduled 24H2 update. A recent tweet from Bob Pony (via XDA Developers) calls attention to the Windows 11 24H2 update requiring the POPCNT CPU instruction for various crucial system files, including the Windows 11 kernel.
The best laptops you can buy today are all equipped with a CPU that supports POPCNT, so if you recently purchased a laptop, there's no need to worry about downloading and installing the Windows 11 24H2 update when it's available. If your PC's CPU dates back to 2008 or earlier, however, you might want to see if it supports POPCNT instructions.