Upgrading to 10.10 and Windows is no longer genuine in Parallels.

I purchased a System 7 OEM System Builder Pack from Microsoft and installed it into Parallels 9 on my Mac running 10.9. Recently, I upgraded my operating system to 10.10 and started getting the message from Parallels to upgrade. Fifteen days later my copy of Windows 7 was no longer genuine. I am quite annoyed that I was not notified by Parallels that this would happen. Almost $200 of my money is now wasted because of this. Microsoft claims I am out of luck because I am using a Mac and if I had a Windows machine they could help me. How can it be that upgrading to a newer system on the same computer causes Parallels to no longer run my System 7? Can anyone tell me if I upgrade wit Parallels 10 can I have my System 7 run again?

At this point I believe I have been robbed by Parallels.

Guy