Which of these is a critical step after modifying the Windows Registry?

Rebooting the system is a critical step after modifying the Windows Registry because changes made to the registry often take effect only after the operating system is restarted. The Windows Registry is a database that stores low-level settings for the operating system and for applications that opt to use the registry. When you make changes, such as adding, modifying, or deleting registry entries, those changes may not be recognized or fully processed until the system has been rebooted.

In many cases, certain system configurations and application behaviors depend on the settings defined in the registry. A reboot allows the system to reload the registry settings, ensuring that any modifications are applied correctly. Additionally, rebooting can help in preventing potential inconsistencies or stability issues that might arise due to immediate changes without a system restart.

While backing up the registry is a crucial safety measure before making modifications, and running a virus scan and installing updates are also important for overall system health, they do not directly affect the immediate application of changes made in the registry. Thus, after altering the Windows Registry, rebooting the system is essential for those changes to take effect properly.