If i choose just c then it cascades to the c:\fs\* anyways.
Yes, version 4.3.1 has a known bug. Selecting a volume via the commandline or the scriptchooser will cause the CommandlineVolumes() volumeboolean to also select all volumes that are mounted on a directory on that volume. It will be fixed in the next release.
I have tried different excludes, but nothing sticks.
Both the examples that Kasuha gave are fine (you need only 1). Please note that there already is an ExcludeVolumes statement in the Settings.MyD file, and MyDefrag will only remember the last one. In other words, you have to delete that one to use your own. Tip: use one of the Debug
settings to see exactly what is happening.