share modes (S) This enables or disables the honoring of the share modes during a file open. These modes are used by clients to gain exclusive read or write access to a file. These open modes are not directly supported by UNIX, so they are simulated using shared memory, or lock files if your UNIX doesn't support shared memory (almost all do). The share modes that are enabled by this option are DENY_DOS, DENY_ALL, DENY_READ, DENY_WRITE, DENY_NONE and DENY_FCB. This option gives full share compatibility and enabled by default. You should NEVER turn this parameter off as many Windows applications will break if you do so. Default: share modes = yes