06)How can we turn on and turn off the serial ports' DTR and other pins.........? When we transfer a file from one computer to another is there need to configure these pins or they are automatically configured?
I'm no guru, but I can tell you that there are different configurations of RS232 . there are specific drivers for them. The wiring is different too. The simplest one is the Xon/Xoff format. Plug that into Google and press enter.
I think bala24 got annoyed because it is clear that you haven't even tried that before asking something out in left field.
Unless you are doing something very custom, there is no reason to worry about turning the DTR pin on/off!!!