New
#41
I have only installed 10159 as an update. If I installed it over an activated 10158, no key was ever asked for.
I installed 10158 twice. The first time, I installed it an an update over 10074, which I installed over an activated Win 8.1. (10130 failed to detect the 10158 update at Windows Update, for me.) The second time, I restored 8.1 and updated it directly to 10158. Neither time did I need a key.
When I clean installed 10147, I needed to use of of the keys posted at this site to get it to activate. I have not used the new keys for 10158 or 10159, but based on past performance, I'd expect the key to work.
I speculate that the more recent builds (10147, 10158, 10159) function like the RTM build will: if installed as an update over an activated qualifying OS, no key will be needed. I wait for information as to whether a new key will ever be made available to legitimate upgraders, to permit Win10 to be re-installed without having to re-install the qualifying older OS first.
(I'll be impressed if MS publishes an official way to do that. They did not do that for Windows 8, although there are simple work-arounds to allow Win 8.1 to be installed directly onto a blank drive, and activated with a Windows 8 upgrade key.)