I'm new to MDL and after browsing a huge amount of threads I've been left with a few unanswered questions I'm hoping starting this thread will answer 1) After upgrading from win 7 to win 8(8.1) then to win 10 on my main PC, I have product keys I believe to be valid for win 7 and win 8. Can I use my win 7 & win 8 installation media and product keys on 2 other machines? 2) After the installation shown above made on my main PC, I used Nirisoft's "Product Key" tool and discovered what my Win 10 product key is (yes i know its done by HWID online), but, should i change my motherboard, SSHD or other key piece of hardware would this "Product Key" actually work during the installation or would the telephone activation be needed after the installation has completed and the HWID activation (in theory) has failed? I apologize to everyone if this has already been covered elsewhere and would appreciate replies showing the link to other relevant threads (if there is any). Thanks to all who help.