Click here . You've heard the story. Microsoft constantly releases updates for the OS and mission critical applications, which fix security vulnerabilities and system stability problems. Click here to see the latest list of applications supported. Most intrusions are easily avoided by deploying security hotfixes.
Most updates fix security vulnerability bugs.
Other updates fix system stability problems. Unless you know about them, you cannot keep up with these changes. Updating machines regularly is the only way to ensure that these problems with the OS and applications are addressed before lightning strikes. With recent events of security intrusions throughout the world, many articles are available about hotfixes and their deployment. Here is a small sample for your information.