The most reliable source is the Garmin MapSource Updates & Downloads page . This provides the latest stable version (typically 6.16.3).
Installing MapSource on a 64-bit system sometimes requires a workaround because the installer often checks for a "previous version" of the software on your machine. garmin mapsource windows 7 64 bit download
Get the MapSource_6163.exe file from the Garmin website. The most reliable source is the Garmin MapSource
If you encounter errors on Windows 7 64-bit, right-click the MapSource shortcut, select Properties > Compatibility , and check "Run this program in compatibility mode for Windows XP (Service Pack 3)." Key Features and Compatibility Get the MapSource_6163
If the installer fails because it can't find an existing version, you can bypass this by installing a small, free utility like Garmin BaseCamp first. BaseCamp installs the necessary registry entries and drivers that allow the MapSource installer to proceed.
While sites like Software Informer or UpdateStar list the 54.4 MB installer, it is always safer to use official Garmin links first. Installation Guide for Windows 7 64-bit