When Windows format a device it will unmount that device.. When that happens MC will receive a message about that and MC will remove it.
When the format is done it is mounted again. and Windows sends a message about that. Or it should. Look like on some system MC do not get the "Device mounted" message again. why I don't know. I have not had time to check why that happens on some systems.
You can type ":rdrive" in the command line field to force a refresh of all drives.
