Can I use a refurbished again when I upgrade?

Solution


I suspect they mean a key attached to a refurbished system.

Typically, those keys are not able to be re-appropriated for other systems, OP. Sometimes they're not actually even legit on the refurb, depending on how morally flexible the seller was. You would need a Windows 10 retail key, as I've never known refurbishers to use a transferable key.
 
Solution
Shame on them for even selling you that license. I've read up on the refurbisher professional, and they usually get those at a stop discount and they are supposed to go through a whole checklist to make sure a computer even qualifies as refurbished. Selling stuff that way is a good way to get in hot water, as selling licenses that way could be considered piracy.