The XP cannot host AD ie you cannot install full AD on it. but yes we can make it dns server to resolve the dns queries in the network but it is advisable to use server platform to make a dns server.
There is utility which is there ADAM with help of which the XP can have features of system having AD but it has limitations and less options.
Active Directory was previewed in 1999, released first with Windows 2000 Server edition, and revised to extend functionality and improve administration in Windows Server 2003. Additional improvements were made in Windows Server 2003 R2. Active Directory was refined further in Windows Server 2008 and Windows Server 2008 R2 and was renamed Active Directory Domain Services. Active Directory was called NTDS (NT Directory Service) in older Microsoft documents. This name can still be seen in some Active Directory binaries.
In Windows Server 2011 it is called Active Directory.
Active Directory
Some books one could use as tutorials for Active Directory are Active Directory Cookbook, Active Directory for Dummies as well as Windows 2000 Active Directory. All have various problem solving techniques one could use and they can be easily referenced.
The following changes are available in Windows Server 2008 R2:Active Directory Recycle Bin Active Directory module for Windows PowerShell and Windows PowerShell™ cmdletsActive Directory Administrative CenterActive Directory Best Practices AnalyzerActive Directory Web ServicesAuthentication mechanism assuranceOffline domain joinManaged Service AccountsActive Directory Management PackBridgehead Server Selection
Active Directory on a Windows Server 2003 Networkhttp://technet.microsoft.com/en-us/library/cc780036.aspx
Active Directory was previewed in 1999, released first with Windows 2000 Server edition
group policy
Active Directory credentials to access SharePoint sites
ntds.dit
ntds.dit
Active Directory Domains And Trusts console