Make sure that you have installed the Samsung Galaxy Grand drivers before going any further.
Once the download mode is charged, connect the Samsung Galaxy Grand Duos device to the PC using the USB cable. (Make sure that the ODIN app is running on the PC).
After you have connected the Grand device to the PC, on ODIN app you should notice that the: ID:COM will be collared yellow or blue color, and the “added” message will be displayed. If not, that’s means the ODIN didn’t recognize the device, and you will have to disconnect the Galaxy Grand Duos device, close the ODIN app, change the USB port from PC and reinstall the USB drivers once again, after that repeat all the steps from the beginning until everything is working as explained above.
Now, from ODIN app click on “PDA” option.
Browse, select and pick the update file from the location where you extracted the downloaded file.
Make sure that the re-partition and f.reset time options are checked.
Now, start the flashing process by clicking on the ODIN app’s “Start” button.
Next, wait until the Android 4.2.2 firmware file is completely installed.
In the end on ODIN app will be displayed the “pass” message and the ID:COM area will turn in green.
Now you can safely disconnect the USB cable.
Reboot the smartphone.