Flashing Firmware on my Arduino Mega2560

Hello all,

I am fairly new to using arduino and such, and I am having trouble running this code in command prompt to flash a new firmware onto the arduino.
I had ran the following code:

python-2.7.9\python.exe\ -m dmf_control__board_firmware.bin.upload -p COM_3 mega2560 2.1

I’m not sure what is meant by the error code shown in the attached image or as to how to solve it. Any help would be greatly appreciated!

Called Process error.png