You are the network administrator for The network consists of a single Active Directory domain named Servers run either Windows 2000 Server or Windows Server 2003. Client computers run either Windows 2000 Professional Service Pack 2 or Windows XP Professional. You need to implement a new software update infrastructure. You discover that security patches, critical updates, and service packs have never been installed on any client computer on the network. You install Software Update Services (SUS) on a Windows Server 2003 computer named Testking5. You must ensure that all client computers receive all Microsoft security patches, critical updates, and service packs. You want to achieve this goal as quickly as possible. Which three actions should you perform? （）(Each correct answer presents part of the solution. Choose three)

• A、Install the Automatic Updates client on all Windows 2000 Professional client computers.
• B、Install the Automatic Updates client on all Windows XP Professional client computers.
• C、Install SUS on a Windows 2000 Server computer.
• D、Modify the Windows Update settings of the Default Domain Controller organizational unit (OU) Group Policy object (GPO) to point client computers to http://testking5.
• E、Modify the Windows Update settings of the Default Domain Policy Group Policy object (GPO) to point client computers to http://testking5.
• F、Upgrade all Windows 2000 Professional client computers to Windows XP Professional.