Which of the following components is essential for a Windows Service to run successfully?

For a Windows Service to run successfully, a service control manager is essential. The service control manager is a part of the Windows operating system that is responsible for managing the lifecycle of Windows services. It handles service start and stop requests, manages the services' dependencies, and tracks the status of services running on the system.

When a Windows Service is installed, it registers with the service control manager, which then manages it according to the specified configuration. Without this manager, the service would not have the necessary infrastructure to be started, stopped, or monitored. This is critical for the functioning of services in a Windows environment, as it provides the means for both the user interface and the kernel to interact with the service efficiently.

The other choices do not provide the foundational mechanism necessary for a Windows Service's operation. For example, a user interface is not required since Windows Services are typically designed to run in the background without user interaction. While an administrator account might be necessary for installing or configuring services, it is not essential for the service's ongoing operation. Lastly, a network connection could enhance certain services that rely on internet access, but it is not a prerequisite for running a Windows Service itself.