I just tried to post this but when I hit Submit it disappeared, so if this ends up being a duplicate please ignore or delete it.
I have installed the latest BaseCamp on two computers one running Win 7 64b and the other XP Home and get very different behavior.... On the XP I downloaded a map from the web and put it in a folder My Garmin \ Maps. I am able to see this map in BC without my Oregon 450 or SD card plugged in. Not so with the Win 7 computer - In order to see the maps I must have the 450 plugged in. How do I make the Win 7 perform like the XP?
It would seem logical to me that an application such as this should be able to use maps from any source - hard drive, flash drive, sd card, dvd/cd, or GPS.