This post is obsolete. You should check out the new updated post: Bypass Windows TCP/IP Limit

As you may have noticed Microsoft still limits your half-open (incomplete/syn packets) connection attempts per second that the system can make. Microsoft has done this since Windows XP Service Pack 2 to keep your computer from being used by dangerous programs such as worms that scan the internet to infect more systems and to keep your computer from being a host of a Bot that connects to IRC that accepts commands to launch Distributed Denial Of Service Attacks (DDoS) against other people and companies they do not like.

Unfortunately for us and companies, this limit effects our internet by limiting the capability of P2P (Peer 2 Peer) applications like µTorrent, BitTorrent, BitComet, Azureus, BitSpirit, eMule (eDonkey network), BearShare, Direct Connect, DC++, ApexDC++, or even P2PTV such as PPLive, PPStream, Sopcast, TVAnts, Peer to Peer, Web server, FTP, and many other applications we love to use but cannot take full advantage of. Basically, you will make uTorrent faster as well as all these other apps you need.

When the limit is hit, You will recieve a Notice in Event Viewer Saying:

EventID 4226: TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts.

This means Vista Has maxed out our connect attempts.

[NEW] vistatcpipuacpatch21 EventID4226Fix for Windows Vista v2.1 for SP1 (build 18000) (32/64bit)

Installation Instructions:

Extract the archive to a directory on your computer.
Windows Vista SP1 32 bit: InstallPatch32.bat
Windows Vista SP1 64 bit: InstallPatch64.bat
Uninstallation: UndoPatch.bat

Please Note! Due to Vista SP1 restriction of using signed drivers only:
Vista SP1 (32/64) requires all drivers to be digitally signed. to bypass this limitation, we use a tool called ReadyDriver Plus v1.1. after install it will bypass the blue-screen and will boot Vista normally.

For those of you who wants to do it manually:
To use this driver you must press F8 at every Windows boot load. Then, in the boot menu, choose the option to disable driver signature. Vista will now boot successfuly.

Credit Goes to [ mydigitallife] | [ Yaronmaor]