Hi, I want to raise the domain functional level from Windows 2000 native to Windows 2003. All DCs are now 2003, but I'm unsure if I can do this while clients are logged on to the network.I.J

As you said, your DCs are all running Microsoft Windows Server 2003 so you can raise your domain functional level without problems. AFAIK, you can perform that while your clients are logged on the network without problems. For more information, have a look to this Microsoft article. This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Microsoft Student Partner Microsoft Certified Professional Microsoft Certified Systems Administrator: Security Microsoft Certified Systems Engineer: Security Microsoft Certified Technology Specialist: Windows Server 2008 Active Directory, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Network Infrastructure, Configuration