In the previous article you have learnt, How to disable NTLM Authentication and here you will be learning to disable Built-in guest account on the computer are joined to domain. you can create group policy object in you active directory to disable centrally.
Open Group Policy Editor -> Navigate to Computer Configuration -> Policies -> Windows Settings -> Security Settings -> Local Policies -> Security Options
right click on “Accounts: Guest account status” and open properties.

Under Security Policy Setting check “Define this policy setting:” and check on Disabled
Apply and OK

That’s it, You have configure your GPO and can be applied to OU to disable the guest account.
once you have applied GPO to OU, run gpupdate on your domain controller server and computers to take immediate reflect or wait some time to auto apply.
verify if the gest account disabled.

Conclusion!!!
In this article you have learnt, how to disable Built-in guest account using Group policy object. In the next article you are going to learn and understand how to Disable Private Mode in Mozilla Firefox browser.