Not strictly a HT setting, but the only one I know that controls the number of “CPUs” in windows is: msconfig (if you start typing it in Start Menu it will show up as “System Configuration”)
tab: Boot, button: Advance Options
Another thing to look at is Hyper-V. I forget some of the details, but when you’re running Hyper-V your Windows is actually just a VM like all the other VMs, but with direct hardware access. And I believe you (or someone) could change the configuration of that VM. For example, changing the reported number of CPUs. It could also be a Hyper-V setting, because I think I remember that Microsoft implemented Hyper-V security options to disable Hyperthreading where it was a security problem.
Thanks for the suggestion…I was sure it was going to solve it. But I disabled Virtualization is BIOS and it’s still 4/4. Although I wonder why even with VT disabled, Task Manager still says Hyper-V support: Yes. Is that reporting a VT capable processor regardless of BiOS setting? Although it is saying Virtualization disabled.
Is this laptop new? If so then did you confirm the CPU name?
You might try to download some linux distro ISO image with live preview, make bootable pendrive and check how linux sees the CPU. To be sure if it is BIOS issue or WIndows issue.