You can do it by a roundabout way : VISTA ==>W7 then W7===>W10. We don't know yet whether W7 will actually have to be activated before the update progresses. VISTA didn't need activation on to install W7 and W7 allows 30 days of use before activation is mandatory. W7 just looked for a previous Windows install as a "qualifying upgrade". You could even just point to the .ISO without even having VISTA installed - you'd get a nice CLEAN install even from an "upgrade" package. You didn't need the physical ISO --one on HDD worked just fine.