My CPU does support VT-x. In Windows 7 before when I run CPU-Z it showed the VT-x in the Instructions list. But now after I upgraded to Windows 10, when I run CPU-Z it does not show VT-x in the instructions list:
However the Task Manager in Windows 10 has a new feature showing one info called Virtualization, it's shown as Enabled but I'm not sure if it's related to VT-x:
So I doubt that CPU-Z just simply does not work correctly in Windows 10. Currently my laptop is full of working space, so I'll try checking out the BIOS to see if it's enabled. Now I need some advice from you especially who has experienced this issue with Windows 10. Thank you!
Best Answer
There's nothing surprising about this. Windows 10 is using the virtualization feature of the CPU, as it says it is. CPU-Z is therefore running on a virtual CPU which does not itself support virtualization.
Before, your OS wasn't using the virtualization feature of the CPU. So that left it available for programs like CPU-Z to detect and use.
Unless nested virtualization is supported (which it isn't in your case) only one program can use the virtualization features. Windows 10 is expected to support nested virtualization shortly, and the preview release as of mid-October already does.