getting it slightly wrong
"Why would Windows 10 invigorate PC sales when all your Windows 7/8 machines are being made to upgrade to Windows 10 for free and the system requirements are pretty much identical?"
in many ways, *THIS* proves a point, but not that windows 10 'up'grades are causing the problem...
"If anything Windows 10 should have stopped PC sales dead in the water, because your old clunker is still able to be upgraded to Windows 10 without you having to do anything."
But the 'old clunker', particularly if it's running Windows 7, is still a "good machine". *THEN*, you look at an 'Ape' (8) machine, or a Win-10-nic machine, and you say *errrgh* and stick your tongue out and DO! NOT! BUY! A! NEW! COMPUTER! because the *OLD CLUNKER* is *STILL* *BETTER* than either of those two systems, and it's getting HARDER to find a 7 machine with "new features" on it.
so why bother buying a new one? *EXACTLY*!
THAT is the reason Win-10-nic is *KILLING* PC sales, same as "Ape" did it. The *NEW* machines are *NOT* perceived as *BETTER*.