Microsoft says I have Illegal copy of Windows 10

I started to use Parallels 10 of Mac a few months ago, and I transferred Windows 7 from my desktop PC.
Yesterday I upgraded my desktop windows from 7 to 10, and I deleted the transferred Windows 7 from my MBPr and transferred the windows 10 to Mac today. I saw a notification to ask me to activate the windows 10 on Mac. Then I phone to Microsoft and ask how to activate it.
However, they told me it's illegal to run windows on mac by transfer the windows from a PC which bought the desktop with pre-installed windows on a PC, not only windows 10, but also the windows 7.
How to solve this situation? Should I need to uninstalled Parallels?
Thank you.

 

This KP doesn't work and is not appropriate for Windows 10 as it refers to Windows XP and in some cases Windows 7 or 8.1 options that are not there in Windows 10. Please read all the other threads on Windows 10 activation issues here!

 

I guess the original question is confusing and so answers are confusing also. I'll try my best to guess the situation and explain...
If these Windows 7 were transferred from PC where they came preinstalled ("OEM" version), then they were licensed ONLY to run on that one PC. It was incorrect and illegal to transfer them to Parallels virtual machine. Unless they were bought originally in store (retail version) in which case they can be transferred. The reason is, that OEM versions are significantly discounted (as low as $10 for license for large OEMs like Dell or Asus).
Seems like the Windows 7 "genuine" state somehow survived the original transfer to the Parallels VM. However, once the Windows 10 were installed, the genuine status was likely lost and that is why you cannot get these Windows 10 activated.
That is the best I can make out of the description. The problem has nothing to do with Parallels, Macbook Pro system or whatever - and all to do with the original type of license of the Windows 7.
If the Windows 7 license was "retail" then Microsoft should help - or alternatively you can restore the original Win7 Virtual machine (you DO have backup?) and try again the upgrade to Win 10. I had upgrades go really bad and destroy my Virtual machines - just to have next, same, upgrade of the same VM restored from the backup to go perfectly fine.
If that was OEM Windows 7, then you probably need to buy new license (Win7 or 8), restore the VM from backup, update/upgrade to Win8/license it with new license and then upgrade. Alternatively, buy Windows 10 license, when available.

 

As stated by Honzall your problem is not Parallels inability to install Win 10 but the fact that your Win 7 was not eligible for transfer from your PC to your MAC. In our case we had to buy several licenses for the MAC users, transferring from one PC to a MAC is an infringement of Microsoft licensing scheme.
Solution is either buy a license for Win 7 (easy online) and install Win 10 online or wait for Win 10 to be released in a store near you.