How do you get a joystick to work on FSX?

I just got a new FSX game after my last computer got some kind of virus and all my files were wiped out. So I went to do my first flight and couldn't use my joystick I had from the the old computer that I no longer have. So I have an old joystick, new computer and new FSX game but can't seem to figure out how to get my new computer to see I have a joystick. So can anybody help me?