µPKI
A Public Key Infrastructure (PKI) is the set of technologies and policies that provide scalable infrastructure for securing internet interactions through the use of public key cryptography. PKI is used in many applications such as IPsec VPN, Code signing, SSL, and secure mail.
µPKI is a C toolkit optimized for embedded devices. It minimizes memory, code and stack usage yet provides a very comprehensive feature set, allowing it to scale up and down to a wide range of devices.

Microsoft Personal Security Advisor
Microsoft Personal Security Advisor (MPSA) is an easy to use web application that will help you secure your Windows NT™ 4.0 or Windows 2000™ personal computer system. Simply press the Scan Now button to receive a detailed report of your computer's security settings and recommendations for improvement.
MPSA will scan your system and build a customized report on items such as: missing security patches, weak passwords, Internet Explorer and Outlook Express security settings, and Office macro protection settings. More details on the specific tests performed by MPSA are available by clicking on the "Features" menu option above.

For each weakness identified on your computer, MPSA provides easy to understand information on the security issue at hand, how to fix it, and links to additional information about the issue. Once you correct a reported deficiency, you can run the scan again and see the results of the change. Running MPSA on a regular basis will help ensure that your system stays up to date and secure.