Which tool is used to view real-time visual graphs of a computer's overall performance?

Performance Monitor is the correct choice for viewing real-time visual graphs of a computer's overall performance. This tool is designed specifically for monitoring various system metrics, allowing users to track performance data over time. It provides a detailed view of system processes, memory usage, CPU load, disk activity, and network performance, all represented in graphical form.

Through Performance Monitor, users can create custom data sets, allowing them to focus on particular performance metrics that are essential for the tasks they are managing. This capability makes it an invaluable resource for system administrators who need to analyze system performance and make informed decisions based on real-time data.

In contrast, Logman.exe is a command-line tool used for managing performance monitoring configurations, but it does not provide a graphical interface for real-time monitoring. Event Viewer is primarily focused on logging events related to system functioning and errors, offering a detailed view of system events rather than performance metrics. Task Manager, while useful for a quick overview of running processes and resource usage, does not provide the extensive graphical analysis and history tracking that Performance Monitor offers. Thus, it is specifically the advanced capability and focus of Performance Monitor that makes it the right tool for visualizing a computer's performance in real time.