I apologize for not following up on the last post. If you still require the Garmin Mapsource software for your computer, then there are two Internet posts that provide instructions on how to install it for free from Garmin:
Download Garmin MapSource for Free and Install Without Media:
http://www.mydigitallife.info/2008/01/3 ... out-media/
-= AND =-
How to Get MapSource Free From Garmin:
http://forums.gpsreview.net/viewtopic.php?t=4802
If one of these methods does not work for you (I tried the first method and it worked for me), then post and I will try to help you out.