Intel's Pentium III CPUs are getting are dinosaurs at this point, and it looks like their time is finally coming to an end – for Windows 7 at least. As initially discovered by ZDNet (via OnMSFT), Microsoft is seemingly dropping support for Windows 7 on PCs still running the aging line of CPUs.
The reason for the move comes down to one particular technology for which Pentium III chips lack support: Streaming SIMD Extensions 2 (SSE2) and its successors. SSE2 is a set of instructions that allows multimedia to be processed in parallel, giving a boost to performance. The feature first debuted with the Pentium 4, but was later promulgated to every mainstream processor.
The issue first reared its head in the March 2018 Patch Tuesday update for Windows 7, which included the following known issue:
A Stop error occurs on computers that don't support Streaming Single Instructions Multiple Data (SIMD) Extensions 2 (SSE2).
While the initial wording of the known issue indicated Microsoft was working on a resolution, the text has since been updated to say:
Upgrade your machines with a processor that supports SSE2 or virtualize those machines.
And though Windows 7 is set to remain supported through 2020, the move lines up with Microsoft's stated policy on security updates. From Microsoft:
Older products may not meet today's more demanding security requirements. Microsoft may be unable to provide security updates for older products.
The first Pentium III chips first hit the market in 1999, so it's not surprising that the hardware may be on its last legs from a support standpoint. And as ZDNet points out, it's likely that the necessary updates to mitigate the Meltdown and Spectre vulnerabilities disclosed earlier this year played a role here as well.
Still, given the Pentium III's age, you're much better off to get your hands on a newer PC with more modern hardware if you're still holding onto Windows 7 as your daily driver.
