Patching the tcpip.sys half-open connection limit on Windows XP SP3

P2P (especially BitTorrent) on Windows XP often find their connections throttled due to the fact that Windows XP SP2 and up impose an aritificial limit of 10 half-open connections. Filesharing and other such decentralized applications need a good amount of half-open connections in order to maintain good peer communication; 10 simply doesn't suffice in these cases.

The tcipip.sys issue has been widely discussed around the Internet, mainly because "Event 4226" Event Log warnings are generated when the connection limit is exceeded.

For users of XP Service Pack 2, several patches for raising the connection limit exist, of which the most popular is probably the LvlLord.de patcher. That program was last updated in 2006, but it also works with the recently-released Service Pack 3 and the post-SP3 Windows updates (one of which updates the tcpip.sys to a newer version 5.1.2600.5625. I just reformatted my computer with a fresh new SP3 slipstreamed install, and I can confirm that the LvlLord patcher still works great:

Hope you find this tip useful!