how to find downloaded software

I bought a nektar Impact LX25+ a while back for an older Mac but with the limitations of the older system lost interest quick. Anyways I recently bought a newer MacBook and wanted to try and get back into creating music. So I downloaded the installer to run the software for the specific midi board model I have, and I successfully downloaded it however, I can't find the software anywhere. Its not in applications, utilities, or downloads. I even tried opening script incase it was maybe tucked away somewhere in there but no luck. If anyone has any knowledge on hooking up midi boards to garage band it would be much appreciated.