The fourth step to balance IIS performance and security is to update and patch IIS regularly to fix any bugs, vulnerabilities, or performance issues that may arise. Updating and patching IIS can improve the stability, functionality, and security of your web server, as well as prevent any potential exploits or attacks that may compromise your web server. However, updating and patching IIS can also have some impact on the performance of your web server, as it may require some downtime, testing, or configuration changes. Therefore, you should update and patch IIS carefully and strategically, such as by following the official release notes and recommendations, backing up your data and settings, testing the updates and patches in a staging environment, and scheduling the updates and patches during off-peak hours.