Re: The bit I don't get with all this...
And thus why it still keeps the older bits up to a point (WIn16 support was dropped with Win64, for example). But that's old stuff, not to mention custom stuff that probably can't be virtualized (like the lathe controlled by the custom card on an ISA bus--support for ISA was dropped with Vista), so that's kind-of "off the back end" territory. But all those custom-built software jobs are still workable, and there's still its stranglehold on the PC games market (in spite of the potential pull power of things like professional gaming leagues).