What type of data did Williams recover from the powered-off victim system?

When investigating a powered-off system, the most relevant type of data that can be reliably recovered is typically in the form of registry files. Registry files contain vital information about the configuration and state of the operating system, user preferences, and installed software. This information persists on the system even after a shutdown and can provide insights into how the system was used, what software was installed, and user behavior.

While cookies and temporary files are associated with user activity and internet browsing history, they are often stored in volatile memory or specific user session data that may not persist after a powered-off state or can be susceptible to deletion and overwriting. On the other hand, system logs can provide historical data but may not always be complete or readily available after a system shutdown.

Registry files are key artifacts in digital forensic investigations, as they provide an extensive overview of the user and system environment at the time of the last shutdown, thereby making them crucial for understanding the context of any forensic analysis.