This feature was implemented in Windows XP Service Pack 2 but has been disabled since Windows Vista Service Pack 2. Since viruses can spread quickly through the network, one of the efforts made by the Microsoft team in Windows XP is the half-open TCP connection limitation to slow the propagation of malware from the infected machine. This is why there are so many viruses that can infect a Windows machine, but very little in other operating systems such as Linux and Mac OS. The Microsoft Windows operating system has always been well known to be easily infected by computer viruses.
