The Windows Pop-up messages are delivered through UDP packetsand this service has low priority in Windows system. As the testingresult shows, Windows system possibly could receive the WinPop-upmessages without showing them up. Moreover, If the personalfirewall is enabled in the system, the WinPop-up message could beblocked by the firewall policies. ln addition, the WinPop-upservice is able to be shutdown freely in the target system.