Information
The built-in local guest account is another well-known name to attackers. It is recommended to rename this account to something that does not indicate its purpose. Even if you disable this account, which is recommended, ensure that you rename it for added security. On Domain Controllers, since they do not have their own local accounts, this rule refers to the built-in Guest account that was established when the domain was first created.
The Guest account exists on all computers that run the Windows 2000 or newer operating systems. If you rename this account, it is slightly more difficult for unauthorized persons to guess this privileged user name and password combination.
Solution
To establish the recommended configuration via GP, configure the following UI path:
Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\Security Options\Accounts: Rename guest account
Impact:
There should be little impact, because the Guest account is disabled by default.