Active Directory (AD) is a key component in preserving the integrity of AD, and if its security is not properly enhanced, it becomes vulnerable to attacks during Windows boot. To be honest, enhancing the security of AD is not a simple task, but through some basic steps, you can improve its security. Please note that what I am discussing here are "fundamental" steps. In terms of security limits, you can always find ways to enhance security, but these methods often come at a cost.