In the case of a company acquisition, what does Microsoft recommend for the Active Directory structure?

Creating a new domain controller and re-architecting the forest is recommended by Microsoft during a company acquisition for several reasons.

When an organization acquires another company, the Active Directory (AD) structure can become complex due to the existence of multiple domains. By establishing a new domain controller, organizations can effectively design and implement a more streamlined AD structure that accommodates the needs of both entities. Re-architecting the forest allows for better management, improves security, and enhances the overall efficiency of user authentication and resource access.

Additionally, this approach addresses potential issues such as overlapping domain names or security policies. By creating a new centralized domain controller, the organization can integrate the two companies' AD environments in a cohesive manner, allowing for unified management of users and resources.

This method also provides the opportunity to adopt best practices in terms of AD hierarchy and organization, ensuring that the combined company can operate smoothly post-acquisition, with minimized risks related to identity management and compliance.