I've been using parallels without trouble for years on my Macbook with Windows 10. I started as a Win7 machine and did the free upgrade. I upgraded to Parallels 13 in August, and then the free upgrade to 14. This is when My trouble started. My parallels loads my Bootcamp partition. After the upgrade Windows via parallels was no longer activated. I've spent 2 days on the phone with Microsoft trying to resolve, and their bottom line is my product key will not activate 10 (Its a 7 key because I did the free 10 upgrade.) They are standing firm, they say I need to buy 10 to get a valid key. I can get my bootcamp to activate with the 7 key. I deactivated it and tried again in parallels and still will not activate. I called Parallels and they say its not their problem, I used my key for bootcamp and they have nothing to do with that or the key activation. Well, I tried activating FIRST in parallels, it never worked there, I tried it directly in bootcamp to see what would happen, and thats when I found the 7 key worked fine there. Clearly this is a Parallels issue. Very disappointed in Parallels on this one... Anyone come across this?
Key activation is tagged to hardware. So it checks the drive ID, number/type of processors, video and RAM, and assigns each a 'priority', and will refuse to activate if the hardware it is seeings 'differs' by more than a certain amount from what was originally seen when the key was used. Now you can control what is 'seen' for the virtual machine by the configuration settings. So you can change how much video RAM is seen, how many processor cores, and how much RAM. It sounds as if possibly the default settings here differ from what was originally used (sounds as if the original settings must have given pretty much 'total' access to the hardware, since it works in bootcamp). So, set your number of processor cores to maximum, RAM to the same, and amount of video memory to the amount that your system actually has, and try again. Several of these will be in areas that Parallels won't like to allocate (since they will degrade the Mac performance). However it then has a chance of accepting the system 'is' the one registered.