I want to run w10 on different partitions of the same computer (same hardver). Do I have to activate w10 only on one partition and I can clean install w10 on the other partition? If activation checks only previously activated installation's hardver ID, can I install w10 on many partition, many hard disks in the same computer?
You can multiboot on the same PC and all of them will be activated automatically. That is if you upgraded first, of course.