The Windows January security update will only be shown/applied if a specific registry key exists. The key is supposed to be created by compatible anti-virus programs. If this update is applied with a non-compatible anti-virus program then it is possible that the os will be unable to boot and have to be re-installed. This registry key can be created manually but be aware of the warning!

Note that this security update contains patches for the Meltdown and Spectre security issues - and these will also not be installed without the required registry key being present.

See https://support.microsoft.com/en-gb/...date-kb4056894