Notes about the $$M file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The $$M file type is primarily associated with '3D GameStudio' by Conitec Datasystems, Inc. Gamestudio is an authoring suite for 2D and 3D multimedia projects; especially computer games. This file type is generated by the level editor as a backup file.