Security Links

Server Security and Hardening

Microsoft Windows Update Your first destination to automatically check your machine has the latest critical patches. Essential.
Microsoft Baseline Security Analyzer A good tool to start off checking any vulnerabilities in your build.
Microsoft Security Tools A whole raft of security tools from Microsoft.

Firewall Software

Zone Alarm Checkpoint Software's ZoneAlarm is probably the best software firewall on the market. The free version is very good. The Pro version includes some extra features including a log showing who has tried breaking into your system.

Penetration Testing

Shields Up! So you think you've set up your firewall well? Try testing it out using the free Shields Up! utility from Gibson Research Corporation.

Spyware Blockers

SpyBot Search and Destroy SpyBot Search and Destroy is perhaps one of the best anti-spyware programs out there. Highly recommended to prevent those nasty pop-up web pages.
JavaCool Software Home of SpywareBlaster and other tools. An alternative to SpyBot.