Microsoft's approach to this environment is Trustworthy Computinga long-term, collaborative effort to create and deliver secure, private, and reliable computing experiences for everyone. Microsoft formed Trustworthy Computing in January 2002, when Bill Gates committed the company to fundamentally changing its mission and strategy in the key areas of Security, Privacy, Reliability, and Business Practices
Security TechCenter
The Security TechCenter provides links to technical bulletins, advisories, tools, prescriptive guidance, and community resources designed to help IT professionals keep Microsoft servers, desktops, and applications up to date and secure
On the MSDN Security Developer Center, you'll find guidance, essential information, and tools for developing secure applications and writing secure code.