Hi ZMan. I'm Greg, an installation specialist, 10 year Windows MVP, and Volunteer Guardian Moderator here to help you.
I'm not aware of those "types" of Windows 10 Pro versions. Can you show me a link to an example which quotes one of these "types?"
But if you buy a discounted key it is likely bogus, since there are no discounts in Windows 10 retail licenses.
Buy only from a major retailer who back all sales, including only Amazon mainline, or Microsoft to be surest. You can buy from Microsoft here:
http://www.microsoftstore.com/store/msusa/en_US...
Then following the gold standard Clean Install in this link which compiles the best possible Install of Windows which will stay that way as long as you stick with the tools and methods given, has zero reported problems, and is better than any amount of money could buy: http://answers.microsoft.com/en-us/windows/wiki...
What makes you think the Product Key you have isn't valid? What is the Activation Status and Edition showing at the top of the page at Settings > Update & Security > Activation?
Run the Activation Troubleshooter in the same location and report back its findings
I hope this helps. Feel free to ask back any questions and keep me posted. If you will wait to choose if I solved your problem, I will keep working with you until it's resolved.
________________________________________________________
Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.