http://www.microsoft.com/technet/security/tools/mbsahome.mspx
MBSA is a free tool that Microsoft provides to scan your system for updates and other security vulnerabilities. It provides links to the updates necessary, along with other instructions to secure your system. I’ve had several problems after implementing these instructions. I followed the instructions accurately, and the steps worked. The problem is that the instructions don’t warn you about possible things that could “break” by following the instructions. I had 2 different web sites break because parent paths were disabled (as suggested by MBSA). I’ve previously had problems after running the IIS Lockdown tool (as suggested by MBSA).
The point is, be sure you remember what changes you make, as you may have to go back and undo them.