Can I reuse a windows 10 product key on the same pc at a later date?

[beaststever]

I recently downgraded from windows 10 to windows 7, I have a windows 7 OEM key so if i want i can reinstall (windows 7 Professional). but I was wondering can I re upgrade to windows 10 past the free upgrade date using that previous product key? And if so will i have to type in the key again or will it automatically recognize me and let me install?

Also A little background knowledge: I originally got windows 10 using 8.1 and then upgrading for free.
Also: I heard windows 10 keys tie to your motherboard so you can reinstall all the time is this true?

 

[wpgwpg]

When you upgrade to 10, Microsoft records your key and motherboard info on its servers. So you should be able to reinstall 10 later if you wish.

Good luck.

 

[Math Geek]

you should be able to go back to win 10 on that pc anytime in the future. it ties to the pc itself so MS servers should activate it anytime in the future.