Rooting the Asus Zenfone 4 is very easy and we will tell you how to do it in five easy steps. Here are the prerequisites.
1. Intel USB driver https://software.intel.com/en-us/android/articles/intel-usb-driver-for-android-devices?page=1
2. File root http://d-h.st/kLh
And here are the steps on how to do it.
1. Install the USB drivers on your computer. Extract the file you downloaded in second step above (Root_Zenfone 4_T001.rar).
2. Ensure that USB Debugging mode is on. Go to settings > About/Software information and touch "Build Number" 7 times to enable it. Then go into USB debugging mode and turn it on.
3. Now turn off your Zenfone 4 and enter to "DROIDBOOT" mode. Do this by holding down these keys simultaneously Power + Vol Up + Vol Down. Your display should now read "Ready for Download". Plug it into the computer now.
4. Open the folder on your computer that was extracted earlier and click on "OPEN.CMD" file.
5. Type this:
fastboot flash update root_zenfone4_v4.2.0.zip
That is it – your Zenfone 4 is now rooted.