Recent preview builds of Windows 11 reportedly support some old processors. So Windows 11 version 24H2 will not be able to run with Microsoft's new changes.
The operating system will crash on startup if your processor does not support POPCNT instructions. 
If you have an old, unsupported PC running Windows 11 and plan to upgrade to 24H2, below we'll see how you can check if your system has what it needs.
Note that running a modern OS with a 15 year old processor is not recommended.
Friends of the operating system have already created applications that allow you to control your computer. Let's look at an open source utility called WhyNotWinAI.
The app will show you if your chip supports the POPCNT instruction.
You can download it by GitHub free.
https://github.com/builtbybel/WhyNotWinAI/releases
