Most stock firmwares comes in single file (.tar.md5) format and can be only loaded in Odin’s PDA or AP field. You must also install the USB drivers in order for Odin to work. USB drivers can be installed directly into your computer by simply unzipping the downloaded file then simply run as administrator to completely install it.
Odin Download Mode
To be able to communicate your phone with your computer while using Odin flashers, your phone must be set into ‘download mode’. Mostly Samsung Android devices can be set in download mode by turning it off then simply by pressing volume down, home and power button at the same time. Then a warning message appear that prompts you to press the volume up button to continue. Once in download mode you may then simply connect your device on to your computer using the supplied USB cable.
Failures of using Odin
Odin errors and flashing failures may only caused by a bad USB cable connection between your computer serial ports. So while during the flashing of stock firmware process, you must ensure that you have a fully working USB cable and a good computer USB serial ports. You may also see to it that you have properly installed the USB drivers.