If you know that you want to enable automatic updates to Windows 2000/XP on all your computers, you can do so by implementing a group policy.

To do so:

• Open Active Directory Users And Computers.
  
• Right-click on your Domain and choose Properties.
  
• Select the Group Policy tab.
  
  To create a new Group Policy, click New, enter a name for this policy, and then press [Enter].
  
• Click Edit to open the Group Policy console.
  
• In the console tree, expand Computer Configuration\Administrative Templates\Windows Components.
  
• Select the Windows Update folder.
  
• In the details pane, double-click on Configure Automatic Updates.
  
• Select Enabled, and then use the dialog box to specify how often you want your computers to check for updates and when they install the downloaded updates.