The checklists and accompanying scripts on the sub-pages below were designed to not break most applications (80/20 rule). The scripts are meant for production corporate environments. Some of the settings reflect the reality of implementing hardening in a production enterprise environment.
I fully support efforts such as the SANS Gold Standard, CIS, NIST, and Microsoft's tools and documentation. I have developed what I feel is a safe baseline of hardening that can be safely implemented in many existing mixed-mode production environments. The hardening settings also takes the need for system administration into account.
Make sure to test these checklists and scripts in a development environment before rolling out to production.