When you install Windows 2000 Service Pack 3 or later on a computer that is running Windows 2000, code is added to authenticate the local Remote Procedure Call (RPC) between the message queuing runtime and the local message queuing service. This code supports the local system account that is also the default account. This code also supports domain accounts for domain controllers. You cannot run the Message Queuing service under the local user account. If you try to run the Message Queuing service under the local user account, you receive the error message that is mentioned in the "Symptoms" section.