Disabling Hyperthreading on an Windows EC2 VM

This post should assist you here https://aws.amazon.com/blogs/compute/disabling-intel-hyper-threading-technology-on-amazon-ec2-windows-instances/

You can only achieve this on specifc EC2 instance types

https://aws.amazon.com/about-aws/whats-new/2018/05/introducing-optimize-cpus-for-amazon-ec2-instances/

Today, we are announcing the availability of Optimize CPUs for Amazon EC2 instances. This feature provides customers greater control of their EC2 instances on two fronts. First, customers can specify a custom number of vCPUs when launching new instances to save on vCPU-based licensing costs. Second, they can disable Intel Hyper-Threading Technology (Intel HT Technology) for workloads that perform well with single-threaded CPUs, like certain high-performance computing (HPC) applications.

Thank Gary. I had gone through this article. Why I got confused is a response from an AWS support engineer for a support ticket we raised - response from the Engineer states " CPU options can only be specified during instance launch and cannot be modified after launch.". If I do this OS level - is this going to be the right way to fix this?