on a fresh install, there is nothing hardware related that "pairs it with a particular CD"... here's a link that will help nail down what the CDis you have:
you said you have the key for the CD you have, but the computer knows it's not the right one. if it were say an OEM key and say a retail CD, Windows will reject the key during the install. the key must match the "version" you have, i.e., OEM, Retail, Upgrade, etc. is it failing activation?
without physically seeing the label with the key on it and the CD, it will be difficult to help further.