Historically, even the most crippling security vulnerabilities can be patched in relatively straightforward fashion. After applying a security update, you’re no longer vulnerable to exploits based on that flaw.
That’s not true of the “speculative execution side-channel attacks” broadly identified as Meltdown and Spectre. Repairing these flaws requires a series of updates to hardware and software, as well as coordination with developers of security software, where incompatibilities between updates can cause crashes and possible data loss. As a result, the process of protecting PCs from these potentially deadly attacks could take months, with a series of patches (and updates on top of updates) from multiple vendors.
In a series of announcements today, Microsoft announced a handful of new tools it recently released as part of that ongoing fight against the Spectre and Meltdown threats. Details and links to the Windows 10 updates are in the “Protect your Windows devices against Spectre and Meltdown” article, KB4073757.
Read more about the new updates to protect against Spectre and Meltdown attacks that were announced by Microsoft on ZDNet.