With MS's "clarifications" published yesterday, the consensus now appears to be that (1) you need a valid Win7/8/8.1 install to upgrade to Win10, and (2) the upgrade will deactivate the prior OS.
Whether or not (2) will be true, only time will tell -- but I want to keep my Win8.1 around and working for some time before I switch over to using Win10 full time.
When Win8 came out, MS offered it for only $40, but nothing along those same lines for Win10 has even been hinted by MS. So, given that Win10 Pro is going to cost $199 (USD), the cheaper route would be to do the Win10 upgrade (from 8.1) for free, and buy a new license for 8.1 Pro.
Since I've only bought Windows versions from MS, I have no idea where to go online to buy a GENUINE Win8.1 pro license key. I don't want to make the mistake of paying a little less money, but for a fake or pirated MSDN key; instead, I need to get a genuine key.
So, I would like suggestions from folks who have purchased Win8.1 pro keys online.
Thanks ... in advance ...