Kari,
One of the big problems with a lot of software packages, including Windows 10,
is that there a lot of
key cracking programs available for download. There are
several that are targeted at Windows. Essentially, they work by trying to unlock
the software using key after key. When they finally find one that works, they use
it. Unfortunately, when someone
with that legitimate key tries to register, the license
gets spit out.
You should be able to present your contract or receipt to Microsoft support and
they should be able to help you. If the first person you reach can’t help you, ask
to ‘escalate’ the matter to a supervisor.
Also be sure to get a case number.
Ultimately, if you have the correct
bona-fides you will be given a new registration.
Windows 10 is mature, and very stable, not to mention being actively supported
in perpetuity. It is well worth it to upgrade.
Hope this helps.
Phil White