Describes the techniques and tools used to find evidence in a personal computer, as well as countermeasures for preventing unauthorized access. The author recommends disk-wiping software to clean up after deleted files, software to enhance on-line security, using a proxy server for on-line anonymity, and buying a second computer solely for Internet connection. Two chapters are devoted to the encryption of both files and entire hard disks. While most of the techniques call for installing software rather than complicated coding, the casual computer user may still find them overwhelming. Annotation c. Book News, Inc., Portland, OR (booknews.com)