Hi Aine,
Here is what to do:
1) Go to C:/Program Files->Fish Tycoon
2) Look for any files that end in .pts ("FishSaveGame1.pts, FTinfo.pts etc)
3) Save them somewhere you like
4) Install Fish Tycoon on your other PC
5) Go to C:/Program Files->Fish Tycoon on your other computer and drop those files inside this foulder.
Carla