Originally Posted by Dhiraj
Can you clear the steps you have followed .I have updated google search ,still no option for all screen mode.
Just update the "google search" app from play store. I got updated to version 184.108.40.2064529.arm
First your google now must be turned on. Then from the app drawer go to "Google setting>Seach&Now>Voice>OK Google Detection"
You'll get three options to select. Select them accordingly as mentioned and you can even record your own voice for activating google now from lock screen.
BUT PLEASE NOTE, you must select the ENGLISH(US) as your language for it to work.
You can change the language from here "Google setting>Seach&Now>Voice>Language".
Hope it helps.