Final answer:
The Event Viewer in Windows aggregates application and system events, differentiating it from the Task Manager, Control Panel, or Registry Editor.
Step-by-step explanation:
The tool that aggregates application and system events in a Windows environment is B) Event Viewer. This utility allows users to view and analyze event logs, which are records of significant occurrences within the system, software, and security events. It can help diagnose problems, track security issues, and understand system performance. Unlike the Task Manager, which monitors running applications and processes, or the Control Panel, which provides access to system settings, or the Registry Editor, which allows users to view and modify the system registry, the Event Viewer specifically focuses on the aggregation and management of event logs.