This behavior occurs because of a race condition. In Windows Server 2003, BITS depends on the EventSystem service. Therefore, if BITS starts before the EventSystem service starts, BITS tries to start the EventSystem service and then waits until the EventSystem service starts. However, even after the timeout period (typically, 80 seconds), if the EventSystem service does not start, the Service Control Manager (SCM) causes BITS to timeout and then adds a message in the event log. Then, you receive the "At least one of services failed to start" error message in the SCM that is mentioned in the "Symptoms" section. After you receive this error message, the EventSystem service may start, and BITS may enter the "Running" state. Because of this behavior, startup may take longer (typically, two minutes more) than usual.