Keep windows from validating word
I understand you issue is somewhat different, only paralel.
You may even have to talk with someone to get it sorted out, but say you have it installed on only 'ONE' computer.
If you upgrade to a new os and then want to down grade back, Take the old os off the trusted pc list before re- installing or it will be seen as still being active and show the new install as pirated.! I have seen Apple's slow down, crash, have hardware failures, just like PC's. I had a similar problem a couple of years back with my XP.
So many problems with system crash, and need to re-install OS that my key was no longer valid.
If Microsoft still says your copy is pirated you will then need to talk with the computer uninstalling the KB update that ends with 1033.
This seems to be known for making legit copies of windows turn sour.