Excuse me, do you have the time? Well you better if you are a Active Directory administrator. Next to DNS, time synchronization is one of the most important dependency of Active Directory. By default, Active Directory will tolerate a plus or minus of five minutes between the clocks of your network. If the time exceeds five minutes, clients will be unable to authenticate, and replication will not occur between domain controllers.
With the release of Windows Server 2008 R2, Microsoft released a Windows PowerShell module for managing Active Directory. To be able to use the PowerShell module you must have at least one domain controller running Windows Server 2008 R2, or at least one domain controller running Windows Server 2003 or Windows Server 2008 with the Active Directory Management Gateway Service installed. The PowerShell module is also available in Windows 7 as part of the Remote Server Administration Tools (RSAT).
Microsoft has released a list of recommended hotfixes and updates for issues that occur in an Active Directory environment using Windows Group Policies or Windows Group Policy Preferences.