Current Environment: All Domain Controllers are W28 R2. 2 Exchange 2010 Servers. Mix of 2003 and 2008 member servers (file services and other applications services) Still have around 30 Windows XP SP3 machines(unable to upgrade because of an old software). All other workstations are Windows 7 and 10 Macs running 10.5 - 10.7 OS X. Are there known issues that I might encounter with current environment, specifically with Windows XP clients?? I assume 2003 and above should not have trouble.

Hi, Thanks for posting in Microsoft TechNet forums. I don't think there will be any compatibility problem regarding Windows XP clients in a Windows Server 2008 R2 Domain. If you need to apply Group Policy Preferences on the Windows XP clients, you will need to install Group Policy Preference Client Side Extensions on them: Group Policy Preference Client Side Extensions for Windows XP (KB943729) http://www.microsoft.com/en-us/download/details.aspx?id=3628 To know more about Functional Levels, we can check the article below: Understanding Active Directory Domain Services (AD DS) Functional Levels http://technet.microsoft.com/en-us/library/understanding-active-directory-functional-levels(v=ws.10).aspx Regards Kevin TechNet Community Support

Hi, Thanks for posting in Microsoft TechNet forums. I don't think there will be any compatibility problem regarding Windows XP clients in a Windows Server 2008 R2 Domain. If you need to apply Group Policy Preferences on the Windows XP clients, you will need to install Group Policy Preference Client Side Extensions on them: Group Policy Preference Client Side Extensions for Windows XP (KB943729) http://www.microsoft.com/en-us/download/details.aspx?id=3628 To know more about Functional Levels, we can check the article below: Understanding Active Directory Domain Services (AD DS) Functional Levels http://technet.microsoft.com/en-us/library/understanding-active-directory-functional-levels(v=ws.10).aspx Regards Kevin TechNet Community Support

Hello, shouldn't be a problem with the functional level BUT if you deploy RODCs then be aware of some requirements for Windows XP. http://go.microsoft.com/fwlink/?LinkID=122974 http://technet.microsoft.com/en-us/library/upgrade-domain-controllers-to-windows-server-2008-r2(v=ws.10).aspxBest regards Meinolf Weber MVP, MCP, MCTS Microsoft MVP - Directory Services My Blog: http://msmvps.com/blogs/mweber/ Disclaimer: This posting is provided AS IS with no warranties or guarantees and confers no rights.

Hello, shouldn't be a problem with the functional level BUT if you deploy RODCs then be aware of some requirements for Windows XP. http://go.microsoft.com/fwlink/?LinkID=122974 http://technet.microsoft.com/en-us/library/upgrade-domain-controllers-to-windows-server-2008-r2(v=ws.10).aspxBest regards Meinolf Weber MVP, MCP, MCTS Microsoft MVP - Directory Services My Blog: http://msmvps.com/blogs/mweber/ Disclaimer: This posting is provided AS IS with no warranties or guarantees and confers no rights.

Hi I have Windows Server 2008 R2 domain functionality level, and server 2003 R2, Windows XP SP3 and Windows 7 machines in my environment I faced only one problem. When I try to configure bypass traverse checking, network stops working on XP SP3 machines. Othervise everythig working fine, with no problem.Best regards Dubravko Marak MCP Blog: Windows Server Administration Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.