After changing DCB info using CommConfigDialog(),I then call SetCommState to take effect these changes to the serial COM device.By closely monitoring(watching) the DCB var., I can see that these changes took effect by calling GetCommState().However, when I close the device(CloseHandle) and then re-opened it (CreateFile), a call to GetCommState() shows that the changes I`ve made earlier with the CommConfigDialog() and SetCommState() are reset to default values with only the BaudRate element being retained correct.It seems that after closing the COM device, the settings made by the SetCommState() to the DCB (before closing it) is nullified except the BaudRate element. Is this an expected behavior? The documentation says that the a COM device, when re-opened, should inherit the values set up from the previous open operation which includes the config settins of the device control block(DCB)...etc. Can somebody from the 'serial' world help me,please. Thanks in advance.