Microsoft raising Windows 11 24H2 system requirement to block CPUs without SSE4.2 and PopCnt

A couple of days ago, we reported about a recently discovered Windows 11 24H2 system bypass trick that works on non-LTSC systems too, though it was initially thought to work only on LTSC PCs.

However, if you want to use the trick above, or some of the other ones available out there, to bypass the Windows 11 24H2 eligibility check on some really old systems, like those sporting Intel Core 2 Duo, to AMD Athlon (the original from back in the early 2000s), then you are going to be out of luck.

Microsoft recently stressed it did not block Windows Terminal on such old CPUs on purpose and there were no conspiracy theories about it. However, it does look more and more like the CPU block on the upcoming 24H2 Windows 11 version is deliberate.

For those who may not have been following the situation, enthusiasts noticed that the Windows 11 24H2 Insider builds from back in February were blocking very old unsupported CPUs from bypassing the check at the start of Setup. Known bypass methods would be stopped in their tracks from working on such old PCs.

Later on, Microsoft also added a message that said "This PC's processor doesn't support a critical feature (PopCnt)" such that users could understand what was leading to the block. PopCnt, short for population count, is an integer instruction that helps count the number of 1s in a binary representation.

Now, a newer build, 26080, seems to raise that block as CPUs without SSE4.2 are also unable to boot into Windows 11.

Something like this was expected considering Microsoft, in a previous build, 26063, had quietly added SSE4.2 to the list of compatibility blocks, and it looks like the implementation is now going into testing with some of the latest Windows 11 preview builds.

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