When you attempt to install Office XP Service Pack 3 to a Windows Server 2003 computer running SharePoint Team Services, you receive:
Setup cannot update file %SystemDrive%\Program files\Common Files\Microsoft Shared\Web Server Extensions\50\bin\CFGWIZ.EXE because it is protected by Windows. You may need to update your operating system for this program to work correctly.
You cannot download, save, and run Office XP SP3 on Windows Server 2003, unless the server has Windows Server SP1 installed (currently in beta at the time this tip was written).
To workaround this problem, either install Windows Server SP1, or press Open when Internet Explorer prompts you with the File Download dialog.