Windows XP Server no longer supports the Quality of Service (QoS) optional component, Admission Control Service (ACS). Setup cannot upgrade your computer if ACS is enabled. Please uninstall ACS, and then run Setup again. Only users with Administrator privileges can uninstall ACS.

Uninstalling ACS does not affect QoS functionality or prevent the installation of policy management systems provided by other vendors. Resource Reservation Setup Protocol (RSVP) accepts other policy management systems that are in compliance with the defined, publicized standards.

To uninstall ACS:

1. In Control Panel, double-click Network Connections.
2. On the Advanced menu, click Optional Networking Components.
3. Double-click Networking Services.
4. Clear the QOS Admission Control Service option, and then click OK.
5. To uninstall ACS, click Next, and then click Finish.