How to del the function of "add guest"?

[Langpaul]

To control the gaming time of my son, I have to lock the apps. But he downloads app with guest user. How can I deletethe function of  "add guest"

[Qatrium]

@Langpaul

What android version you're running? You can find out from Settings -> About phone

[Langpaul]

7.1.1

[Qatrium]

@Langpaul

There's no option on your phone to disable "Add guest" feature. However, you can achieve this my some advanced tinkering of your phone using ADB and fastboot tools. No rooting is needed though. Bear in mind that you are doing this at your own risk, as the misuse of these tools might brick your phone.

A detailed guide can be found here.

[Langpaul]

I cannot save file after I add 

fw.show_multiuserui=0

 to build.prop file

In /data , there is no /system, just /play

[Strampke]

There is another option.

You can add 5 guest accounts.

Do so!

And lock the guest accounts with a nice password like: naahnahnahnaaanah!

BTW smart kid!

Makes me remebember how I tried to lock out my sons from the Windows computer by setting a restricted time to enter.

It took them less than a day to find out and set the systemclock to another time.

What I learned from that?

Don't try to outsmart your kids.