On a side note, if the computer was refurbished, they might have replaced the motherboard on it which would cause DMI issues on HP computers. So it's possible that you're getting an incorrect key because of the mobo. If that is the case, you would need to contact whoever refurbished that computer for warranty support. I believe the warranty 90 days on most refurbished products.
- Although I do work for the Geek Squad, all comments and opinions are my own.