**It can be enabled without rooting, by pushing the edited file from custom recovery.**

You must Have `jdk`, `Android sdk`(including platform tools) and proper `adb drivers` installed.  

 1. First, download TWRP Recovery for Android one (sprout) and paste it in   
`c\program files\andrdk\platform-tools`. Rename it to "twrp".  
 2. Connect your device.  
 3. Right click on platform-tools folder holding left-shift and click on 
`Open command window from here`. Then type `adb reboot bootloader`. This will boot phone into fastboot mode.  
 4. Then type `fastboot boot twrp.img`. This will boot the device into 
TWRP recovery temporarily.  
 5. In recovery click `mount`, then check `system`. Then type, 
`adb pull /system/build.prop`. This will copy the `build.prop` into the platform-tools folder.
 6. Open the `build.prop` file using notepad++ (simple notepad may corrupt the file). Then add these lines at the last  
 
        fw.show_multiuserui=1
        fw.max_users=3

Then save it.

 7. Then type, `adb push build.prop /system/`. This will push the edited file.
 8. Now type 

        adb shell
        cd system
        chmod 644 build.prop
 
 9. And last go back to recovery using navigation key and click reboot then click system.

Now, you have enabled multiuser without root.

**NOTE:-***Do everything at your own risk ,I will be not responsible for any damage to your device.
I posted this because this worked for my Android one ..*