Register problems ?

[cobro]

I own a copy of call of duty 1 and call of duty 2

and i was trying to register the key code on steam but i get not valid how can i add them to steam ?

[SSWeltenfeind]

No, you cannot add them to Steam.

[cobro]

okey thats a bummer :( i would really like to just add them and have them on my steam account.. Well that's that thank you for your reply