The following sites provide information on security issues.
Microsoft's official security site providing the latest security news, fixes, and links.
Site: http://www.microsoft.com/security/
SANS is a research community, composed of over 156,000 security personnel and system administrators. Here you'll find the latest security news, events, resources, and more.
Site: http://www.sans.org
Windows 2000 Magazine's central site for IT security news, FAQS, files, articles, and more.
Site: http://www.winnetmag.com/WindowsSecurity/
http://www.microsoft.public.security
http://www.microsoft.public.win2000.security
http://www.microsoft.public.windowsxp.security_admin