I don't think that the BIOS has anything to do with how Windows looks at a dual core processor. It's still one processor technically, but with two cores as each of these so called 'processors' still rely on a shared control unit to feed it with data.

But when you actually have two or more processors, like in a SMP system, you need an OS that can send data to the number of processors you have.

The whole thing with the renders stopping sounds more like software than hardware, CPUs don't timeout like internet does, though they do freeze.