For greater forensic capabilities vendors like Guidance and Accessdata offer software solutions that organize your suspect's documents, emails, and instant messages; index complete drives for searches; crack encrypted passwords; and much more. (See also Rules of Evidence: Digital Forensic Tools.) Personally I recommend and use FTK 2.2 for its easy-to-use tools, high processing speed and excellent technical support team.
In the end I tell people computer forensics is more of an art than a science. Whether you make a copy and use Windows Explorer to find evidence or purchase tools like Encase and FTK to make searching easier, it all comes down to taking your time, connecting the dots and sorting through a lot of information.
Brandon Gregg is a corporate investigations manager.