Book excerpt: When an IT security configuration checklist (e.g., hardening or lockdown guide) is applied to a system in combination with trained system administrators and a sound and effective security program, a substantial reduction in vulnerability exposure can be achieved. This guide will assist personnel responsible for the administration and security of Windows XP systems. It contains information that can be used to secure local Windows XP workstations, mobile computers, and telecommuter systems more effectively in a variety of environments, including small office, home office and managed enterprise environments. The guidance should only be applied throughout an enterprise by trained and experienced system administrators. Illustrations.