I know this has been discussed in various forms, but it seems to keep coming up in a lot of blogs I read online daily. This is from Windows 7 News and dated today April 14 , 2009...JavaJolt
W7 W7
W7 W7
Microsoft is limited the number of half open connections in all their operating systems since Windows XP Service Pack 2 including Windows 7 in an effort to reduce the impact of the individual system on the distribution of malicious software. This can mean unnecessary slow downs on computer systems that operate applications that establish lots of connections in short time. This is for example the case with P2P applications and other server applications.
Patches have been released for all affected Windows operating systems including Windows 7. Half Open Limit Fix is just one application that can patch the tcpip.sys file to change the number of half open connections on the Windows 7 operating system.
(http://windows7news.com/wp-content/uploads/2009/04/halfopenlimitfix.jpg)
The application will display the current half open connection size and offer another field that can be used to change the limit. The developers are suggesting setting the limit to 100. A good indicator if patching the tcpip.sys file is necessary at all is to look at the Event log to see if there are any EventID 4226 errors (TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts.). If that is the case the computer is slowed down by the limit and it is recommended to patch the file to increase the output.
The software is listed to work with both 32-bit and 64-bit editions of Windows 7 Beta. Could work with later builds as well.