In case of confusion C Maps are for the stand-alone client for Windows/Linux and Flash Maps are for the flash client.
If you don’t know how to install the map files follow one of the guides.
Updated for Winter Update 2015!
If you can’t figure out how to install the map files your self i made a small tool that does it for you.
It will both download and install for you either with or without marks.
Remeber this tool only work for the stand alone client.
Sorry for delay i have updated the installer to work with the latest download links.