Microsoft releases Windows 10 Spectre fixes for Haswell, Broadwell and Skylake CPUs

The best way to install Microcode updates is to utilise motherboard-level BIOS updates, patching the firmware at the source in a way that is OS-independent and will operate when user re-installs an old OS or switch over to a niche Linux distribution.  

In the wake of Spectre Microsoft has decided to release Sprectre mitigating Microcode updates using Windows/Microsoft Update, with their latest KB4091666 update adding updates for Skylake, Broadwell and Haswell series CPUs, protecting Intel CPUs that were released as far back as 2013. 

Spectre mitigating updates have already been released for Intel’s newer Coffee Lake and Kaby Lake platforms through Windows, offering coverage from Haswell to Coffee Lake. Future Intel CPUs are expected to ship with mitigations in silicon, with further Windows updates providing fixes for Ivy Bridge and Sandy Bridge era systems. 
 
While BIOS-level changes are preferable, there is no getting around the fact that many of these older systems are out of warranty, and that motherboard manufacturers and OEMs have limited staff to dedicated to the task, making the update roll out slow for older systems. Microsoft’s updates are expected to service older systems, as motherboard manufacturers have long since stopped making BIOS updates for Sandy Bridge era systems, making OS-level microcode injection the only viable option for protection.