w10pro upgraded, roll backto 7pro, install w10 on new ssd at a future

AMD 8 core 64 bit system I built.

1. installed free, w10pro upgrade.
2. made a disk image and repair cd.
3. can I now roll back to w7 64pro. and still keep an option to
latter do and clean & fresh w10pro install to a new ssd. (will my digital verification still be valid?
without all the fragments from 7 and my old programs?
Thank you.

Until you change your Motherboard. .. Ms stores hash IDs(dont know which) as a proof of activation on their servers.
U so ever have upgraded to windows 10 make sure to sign in with Microsoft account instead of local account.. this way even if a hardware change is made to a computer you can still activate windows in case of Failure.