What can I do to protect my PC from the Meltdown and Spectre flaws?

John has an old Sony Vaio PC that seems unlikely to receive a firmware update. Should he replace it?

My Microsoft Surface Book is protected against the Meltdown and Spectre security flaws, but my Sony Vaio Pro remains vulnerable to Spectre. Both laptops run Windows 10 and have been updated via Windows Update. The Surface Book's BIOS has also been updated by Microsoft, but there is no BIOS update for the Vaio - and, I suspect, for millions of other machines.

What is the risk of continuing to run the Vaio with this known critical vulnerability? Is there another way to mitigate it? Or, in the end, do thousands of people have to dump otherwise good machines and buy new ones? John Piatt

It's too soon to say. Bear in mind that, so far, there are no known exploits for these vulnerabilities, so the current level of risk is low. Companies will try to defend against threats as and when they appear. In the short term, we'll just have to see how well that goes.