What action must be taken if a change made in the Computer Configuration node of a GPO does not apply immediately?

The correct action to take when changes made in the Computer Configuration node of a Group Policy Object (GPO) do not apply immediately is to restart the computer. This is because Group Policy settings are typically applied during system startup and user logon, and some computer configuration settings require a restart for the changes to take effect.

When a computer is restarted, it processes the Group Policy during boot, which allows any changes to the configuration to be fully applied to the system. This is especially true for policies that affect core system settings or configurations that cannot be adjusted without rebooting the operating system.

While logging out and logging back in, waiting for a period, or using the Group Policy Update command can also apply some settings, they may not ensure that all the changes have been applied effectively in cases where a restart is necessary for complete execution of the policy. Hence, in situations where immediate application is required, restarting the computer guarantees that all settings are enforced consistently.