Today I found this thread and decided to try an online chat with MS. The lady seemed to understand my problem and was very helpful - she just gave me a new product key and said to enter it under Parallels rather than Bootcamp (I've not tried to reboot yet, I suspect it won't work so I will not be bothering until I really have to). Using the command line route above this worked. I'm now reactivated under Parallels at least.
Unimpressed with the hassle, but impressed with the quick MS service to be fair.
Lucky you. This was my experience, I couldn't even get a coherent answer:
Hi, thanks for visiting Answer Desk! I'm Cherry L.
10:42 am
Hello
10:42 am
Hi, how may I help you?
10:42 am
I have a fully activated copy of Win 10 running on my Mac under Boot Camp but I'm unable to activate the same copy running on a virtual machine under Parallels
10:43 am
Used to work just fine when it was Win 7 Pro
10:43 am
Oh I am sorry to hear that
10:44 am
Sorry but you need to go to apple store for them to activate it for you.
10:45 am
Apple store won't activate Windows 10
10:46 am
Apple doesn't make Parallels, and it's working fine under Boot Camp, as I said
10:46 am
Yes they can because they have a tools for that and there are some device to mac we cant fix
10:47 am
I was on the phone a while ago and one of your reps gave me a new key but it doesn't work
10:47 am
No they can't, please don't insist
10:47 am
Sorry but we cant do that for you. Only the apple store can activate it for you.
10:49 am
Are you able to transfer me to someone who can actually understand my problem, you don't seem to.
10:49 am
The Apple store can not activate Windows 10 and the fact that you are suggesting it tells me you are out of your depth.
10:51 am
Is it okay if I will give a phone number for our windows department?
10:52 am
Sure, that would help.
10:53 am
1-800-642-7676
10:53 am
Thank you for contacting Microsoft answer desk have a wonderful day!
10:54 am