same ports? , is it plugged into the computer LOL
did you use the detect new software program yet?
...anything special in the instrucions
...are you sure it is compatable with your computer system?
... call the place of purchase and if worse comes to worse return and make them get one that works, ensure you test it at the store before leving
What model keyboard?
is it wireless, USB, etc...
Have you checked your BIOS to see if your USB ports are enabled?
Pretty much what Drew said, it is hard to fix your problem if we don't know the specifics of your problem.