How would I enable vt for Windows 7?

Thanks
VT requires processors that support the feature.
If your processor does not support the feature you will not be able to enable virtualization.
As Mokubai has pointed out, your processor (Pentium T4500) does NOT support virtualization and so you will not be able to enable virtualization, no matter what OS you use.
Virtualization is still possible with a product such as VirtualBox. However, your options are limited, since this option is required to emulate other instruction sets than the one in your CPU.
These are the limitations:
In short, it is not recommended to perform hardware virtualization on your machines that do not support VT-X, because it is more painful than helpful.