Really, the easiest way would be to just download the update again using the laptop. The link you used the first time should continue to work for awhile. AFAIK, there is no limit to how many computers you can install the maps on, but you can only install them on one GPS.
Otherwise, you could try copying the files directly but you might run into some issues. I believe the location of the files may vary with your version of Mapsource. On my computer they are located in \Garmin\CNNANT2009