Microsoft has released a security patch for Windows 10 Version 1709. The security patch block attempts by hackers and malware to exploit the Meltdown and Spectre. The update name is KB4056892. It should be part of normal Microsoft auto update routine.
If you’d like to download the update as a separate install then it can be found on Microsoft Update Catalog using the following link:
http://www.catalog.update.microsoft.com/Search.aspx?q=KB4056892.
If you are using a Windows 10 PC with Intel 64 bit CPU please use the
2018-01 Cumulative Update for Windows 10 Version 1709 for x64-based Systems (KB4056892)
Also check with your Anti-Virus program if it is compatible with the new update. Avast has confirmed that it is compatible with the Microsoft update. Instructions to upgrade your Avast Anti-Virus can be found below:
https://support.avast.com/en-us/article/Meltdown-Spectre-vulnerability