What kind of virtualization you tried and under what OS? For example, if you install the Hyper-V feature of Windows 8 or 10, all ultils will fail to detect virtualization capability of CPU, because MS hypervisor is already loaded at boot and takes control over virtualization (even if no VMs configured). So if you want to use other solution, uninstall Hyper-V first.
Thank you! That explains everything.
So the problem was just that I did not understand the process.@