Windows 11 24H2, new confirmation: CPUs without SSE4.2 and POPCNT will be blocked

Microsoft is raising the level of selectivity for i processors compatible with Windows 11 24H2. On the next version, the Redmond company has decided to block installation on obsolete CPUs that do not support SSE4.2 and POPCNT instructions, considered crucial for the correct functioning of the operating system.

The novelty was discovered in February and had raised some doubts because it seemed like an involuntary move on Microsoft’s part. Now, however, it is clear that it is a thoughtful choice, probably aimed at ensuring optimal performance and an uncompromising user experience. Through the block, cannot be circumvented differently from other restrictions due to system requirementsold architectures such as Intel Core 2 Duo and the first AMD Athlons are excluded.

Windows 11 24H2 will not work on CPUs without SSE4.2 and POPCNT

The features in question, SSE4.2 And POPCNT, are hardware instructions integrated into processors that significantly improve computing efficiency and memory management. SSE4.2 (Streaming SIMD Extensions 4.2) is an instruction set that accelerates certain types of operations, while POPCNT (Population Count) is an instruction dedicated to quickly counting set bits in a binary representation.

Starting from build 25905 of Windows 11 24H2, Microsoft blocked CPUs without PopCnt, introducing an explanatory message during installation some time later. Furthermore, from build 26080, the block has also been extended to processors without SSE4.2, further widening the range of incompatibility. This decision could lleaving behind a portion of users with very obsolete hardware, but Microsoft seems determined to preserve the integrity and performance of its operating system even at the cost of sacrificing backward compatibility with outdated architectures. However, this is a fairly expected evolution, given that from the preview build 26063 Microsoft had added the absence of SSE4.2 instructions to the operating system’s list of compatibility blocks. This block has now been included in testing in the latest released versions.

Anyone wishing to check whether their old PC is compatible with Windows 11 24H2 can follow this guide that we prepared last February.