I wish people would write out what's going on other then calling for help....
So to sum up, it goes like this. You bought a machine at some point. It probably had windows on it already. Then you got a copy of win8 from staples at some point. I'm fuzzy as to what key the keyfinder looked up. The one on the machine, or the copy of windows 8 that you bought? You said the computer doesn't have a sticker on it, but the copy of windows 8 that you bought should have a sticker. You have to use the key on the COA. Period. The one the keyfinder finds might just be the OEM key used, read my previous post for that info.