Active Directory Guides - installation, structure, GPO, replication, and troubleshooting on Windows Server 2025

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New to AD

What Is Active Directory?

How AD DS works: forests, domains, domain controllers, Kerberos, and the components every operator needs to understand.

 Install

How to Install Active Directory on Windows Server 2025

Step-by-step from bare Windows Server to a working domain controller – with the decisions that matter before you dcpromo.

 Health check

Active Directory Health Check

Full checklist for domain controllers – replication, SYSVOL, DNS, time sync, FSMO roles, and Event Log triage.

 Troubleshoot

Active Directory Replication Not Working

Systematic diagnosis from repadmin output to error 1722, USN rollback, and site-link configuration failures.

Foundation

4 articles
What Is Active Directory? How AD DS Works on Windows Server 2025 Active Directory Structure Explained: Forest, Domain, and OU How to Install Active Directory on Windows Server 2025 Active Directory Post-Install Checklist: 9 Tasks Before You Go Live

Architecture

4 articles
Active Directory Sites and Services Explained FSMO Roles: What They Do and How to Manage Them How to Design Active Directory OUs Without Breaking GPOs Group Policy in Active Directory: How GPO Processing Works

Troubleshooting & Recovery

4 articles
Active Directory Replication Not Working: Diagnose and Fix SYSVOL Replication Issues: DFSR Troubleshooting Active Directory DNS Problems: SRV Records and Resolution Failures Active Directory Time Synchronization: Fix PDC Emulator and Clock Skew

Health & Maintenance

2 articles
Active Directory Health Check: Full Checklist for Domain Controllers DCDIAG Explained: How to Read Domain Controller Diagnostics

Managing DNS on your domain controllers? The Windows Server DNS cluster covers zones, forwarders, scavenging, and troubleshooting server-side resolution failures.

Windows Server DNS →