Microsoft has withdrawn Windows 7 operating system support for computers with Pentium III or earlier processors, even though security support was originally scheduled until 2020.
A bug within the not-SSE2 CPUs forced Microsoft to take this radical decision
Microsoft company has given up on updating these computers after finding a bug that blocked the Windows 7 computers running with Pentium III CPUs or other CPUs that do not have the Streaming SIMD Extensions 2 (SSE2) instruction extension within their processing abilities.
A notice about this issue for SSE2, an instruction set included in Intel’s processor architecture, was included in the March Windows 7 Monthly Fix and Upgrade Summary.
In addition to that, the release it stated that “Microsoft is working on a solution and an update will be provided shortly” to address the issue.
This message remained in the improvement briefs until June 15th, after which the company changed the message cited as “Upgrade computers with a processor that supports SSE2 or virtualize those computers.”
Microsoft no longer refers to that issue after the June update.
Microsoft seized Windows 7 support for computers with Pentium III or earlier CPUs, despite initial announce to support them until 2020
Back in 2016, the company announced that it was extending Windows 7 security support until January 14th, 2020, which meant that security patches would continue to be released to stop malware attacks even if they did not continue to add improvements.
However, malware on not-SSE2 devices has modified the Microsoft’s original plans and the company is now recommending users of computers with Pentium III or earlier to upgrade at least to SSE2 CPUs.
SSE2 instructions first appeared in Pentium 4, so computers with Pentium III or earlier processors do not currently receive this updates.
It is not known at the moment which is the origin of the failure that blocks these computers, although it can be related to the patches against Spectre and Meltdown, according to some IT security experts.