Problem extracting (i think)

I have recently got a download and extracted this to the file of microsoft games>FS2002 this worked fine and the plane is fly able in the list. However when i download more of them i do exactly the same thing and nothing happens, why is this?

\I don't know why but you could extract it to another destination (eg. Flightsimdownloads) and then move the aircraft file from there to the aircraft directory