Unlike the extremely expensive tests Dr. House runs to diagnose a patients problems, Sysnternals is free. Like the MRI, SysInternals can tell you everything you ever needed to know and more. For this reason I recommend you use the link to Microsoft at the top of this page to find what you need. I watched the process evolve after Microsoft bought SysInternals. I would like to give Microsoft a "DIGITAL HIGH FIVE" not only offering these tools for free but for the great job they did on their web site presenting them to the customer.
File and Disk Utilities - Utilities for viewing and monitoring file and disk access and usage.
Networking Utilities - Networking tools that range from connection monitors to resource security analyzers.
Process Utilities -Utilities for looking under the hood to see what processes are doing and the resources they are consuming.
Security Utilities - Security configuration and management utilities, including rootkit and spyware hunting programs.
System Information - Utilities for looking at system resource usage and configuration.
Miscellaneous Utilities -A collection of diverse utilities that includes a screen saver, presentation aid, and debugging tool.
In your case I hope the patient lives.