lay-out

[zaiko]

all the time I start MC i have the split window . How can I have one window all the time ?

[Mathias (Author)]

MC is designed to be used in a dual panel setup. where the focus panel is the default target location and the opposite panel is the default target location.
MC is not designed to be used in single panel mode. Running with only a single panel a lot of features will unusable, and minimizing one panel to zero size only hides it. It is still there and can be used without you seeing what you are doing and that can be very dangerous..  because of that MC never saves panel size that are zero between restarts.

[zaiko]

well that is very confusing ! I used directory opus before and that looks more logical.

[Mathias (Author)]

It might be confusing if you never used it. But it is also very effective when you learn to use it.

(Actually the original Directory Opus (on Amiga,  many many year ago) also used dual panel setup, So it is not a new idea)