I think other than what I mentioned you're pretty much out of luck. Microsoft shut down the cdn's they had on Digital River and removed them from their Azure storage last month so if you have a product key that is an OEM, System Integrator or Volume Licence type you better hope you still have a disc or iso if you want to reinstall. Retail keys are fine on their recovery site (well mostly). How they will verify Windows 7 owners when the free upgrades for 10 roll out is a bit of a mystery.
I will call MS support tomorrow (at least i have one in my country so kudos to them) and i will ask Also CD KEy that is on back of my notebook doesn't match with my key that ProduKey reads from my OS. And CD Key on my notebook is a bit damaged so i can't read one number/letter.