Windows Vista tcpip.sys Connection Limit Patch for Event ID 4226
Apparently in Windows Vista, Microsoft still enforce and hard-limit (hard coded in tcpip.sys) the maximum simultaneous half-open (incomplete) outbound TCP connection attempts per second that the system can make, as in Windows XP SP2, in order to protect the system from being used by malicious programs, such as viruses and worms, to spread to uninfected computers, or to launch distributed denial of service attack (DDoS). When the limit is hit, in Event Viewer, there will be such an entry:
EventID 4226: TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts
Unless Windows XP SP2 which has 10 maximum incomplete concurrent connection attempts limit per second, Windows Vista default limit is based on which edition of Vista users are using. For example, Home Basic has maximum limit of 2, and Vista Ultimate is 25 per second. Normal Windows Vista users should not face any problem or slow network connection with the half-open connections limit. However, heavy P2P (peer-to-peer) applications users such as uTorrent, BitTorrent, BitComet, Azureus, ABC, eMule (eDonkey network), etc, or P2PTV such as TVants, PPLive, PPStream, Sopcast, etc may face some error or slow download and upload speed due to this limit.
Due to enhanced security, to fix or crack the TCP concurrent connection limit in Vista is not as easy as in Windows XP. To remove maximum concurrent half-open connection limits in Windows Vista, apply the patched tcpip.sys with the following steps:
- Download patched tcpip.sys: Vista TCP/IP and UAC Auto Patcher (patched tcpip.sys is contained inside the archive)
64-bit tcpip.sys or 32-bit tcpip.sys. Alternative download link for 32-bit and 64-bit. - Open command prompt, and run the following 2 commands:
1. takeown /f c:\windows\system32\drivers\tcpip.sys
2. cacls c:\windows\system32\drivers\tcpip.sys /G “username”:FReplace username with the actual user name that used to log on to Windows Vista currently.
The second command can also used improved lcacls:
icacls c:\Windows\System32\drivers\tcpip.sys /grant “username”:f
- Disable the TCP/IP Auto-Tuning feature by running the following command in command prompt:
netsh int tcp set global autotuninglevel=disable
- For 64-bit Windows Vista (x64), the integrity checks need to be disabled as it need all drivers to be signed. So run the following command in DOS prompt:
bcdedit.exe -set loadoptions DDISABLE_INTEGRITY_CHECKS
Note: Above command no longer supported, and users require to press F8 on system startup to bypass driver signing integrity check.
- Replace the tcpip.sys in C:\windows\system32\drivers folder with the patched tcpip.sys downloaded from step 1 (remember the use the correct x64 or x86 version）. Normally, this procedure can be done by simply login to Windows Vista with administrator account. However, if the process failed, reboot the computer and then press F8 to boot up in Safe Mode, and then copy and paste overwrite the tcpip.sys.
- Next, the maximum number of TCP half complete connection limits need to be set in registry. Open registry editor (regedit), and navigate to the following registry key:
HKEY_LOCALL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
- Right click on the right pane, select “New”, then select “DWORD value”. Enter the new value name as “TcpNumConnections” (without quotes).
- Double click on TcpNumConnections registry value, and modify the value data to the desired maximum TCP/IP connection limit that you want to allow, in decimal value. For example, enter 500 as the value data for TcpNumConnections. You can use any limit that you prefer. Alternatively, download this registry registration file (another download link) that when executed, will set the TCP simultaneous connection limit to 16777214 (you can always modify the value in the file or in the registry after applied).
- Restart computer.
New: Windows Vista Event ID 4226 Auto Patcher
Windows Vista Event ID 4226 Auto Patcher has been renamed as Vista tcpip.sys and UAC Auto Patcher, which now has more than 6 versions of auto patcher download links for different versions of tcpip.sys with the release of various hotfixes and SP1. Visit here for details.
New: Half-Open Limit Fix (Automated tcpip.sys Patch using Test Self-Signed Certificate)
Also Available – Driver Version: CrackTcpip.sys for Vista SP1 v.668 – a non-patching method to bypass TCP connection limit.
Also available is TCP/IP auto patcher for 64-bit (x64) Windows Vista SP1.
Gui Version: VistaTcpPath TCP Auto Patcher which works for Vista RTM (non-SP1) version of tcpip.sys.
Old Version:
Version 1.0
Version 1.2
Version 1.3
Version 1.4
Version 1.5
With thanks to YaronMaor for batch script.
The TCP connection limit which trigger Event ID 4226 has now increased to 500 (or any other value you set), and will likely fix the error for re-occurring again.
Related Articles
- Windows Half-Open Limit Fix (Patch) Free Download to Remove XP, Vista and Server 2003 (32 and 64-bit) TCP 4226 Connection Attempts Limit
- Windows XP SP2 TCP Connection Limit (Event ID 4226)
- Download Vista tcpip.sys and UAC Auto Patcher to Increase TCP Connection Limit
- Half-Open Outbound TCP Connections Limit Removed in Windows 7 and Vista SP2 (No Patch Required)
- Download TCP-Z V2.4 Build 20090108 to Patch tcpip.sys of Windows 7 (32-bit and 64-bit Support)
- CrackTcpip.sys Driver for Vista SP1 v.668 to Patch tcpip.sys 6.0.6001.17052
- TCP/IP Has Reached the Security Limit Imposed on the Number of Concurrent TCP Connect Attempts Error on Windows Vista
- Universal Tcpip.sys Patch Auto Patcher Free Download (V1.2 Build 20090409)
- VistaTcpPatch Windows Vista TCP Half Open Limit Auto Patcher GUI Version
- How to Enable Concurrent Half-Open TCP Connect Attempts Limit in Windows Server 2008 and Vista SP2 or Windows 7
Entries (RSS)
May 31st, 2009 23:07
[...] Note: If you’re using Windows Vista please read this article. [...]
May 4th, 2009 03:18
[...] znieść ograniczenie na liczbę połączeń w Windows Vista (tzw EventID 4226 [...]
April 27th, 2009 00:39
Hey. I wish i could use this. I did everything as listed above, but i cant replace the tcpip.sys file in my system. I really dont know how. I tried to do it as administrator, i tried to do it in safe mode, but always without success. Do anybody has any idea, please?
April 26th, 2009 01:16
[...] cat timp ai uTorrent pornit. Ai nevoie de patch-ul de aici(xp) .Setezi intre 43 – 50 de conexiuni AICI pt. vista __________________ Vreau [...]
April 19th, 2009 04:46
I just try this shit and crashed my PC forcing me to insert the vista disc and restore the PC. My PC is a self assebled one vith a retail version of win vista ultimate edition. I tell this: if you are not able to recover and advanced manage your pc DO NOT TRY this or be advised to do a FULL BACKUP of your system. My was a really bad experience. Tried it also on an HP laptop: SAME RESULT. The OS doesn’t start and give blue screen. I’m an assembler and not a novice. Be careful using this “patch”. Man advised, half saved! Bye
March 23rd, 2009 19:30
I followed the instructions here, but when I re-booted my laptop I was given the option to repair or reinstall Vista. Clearly this doesn’t work for everyone, even if you follow the instructions carefully, so beware! Thankfully I’d had the presence of mind to create a system restore point before doing any of this, so my system reverted to where it was before I started tinkering with it. I won’t be attempting this again in a hurry.
March 13th, 2009 14:34
Well it has taken me 3days of reading and working up the courage to try this out. Like alot of ppl here i upgraded from xp to vista and was seriously sadened when i tried to use utorrent with vishita excuse me vista. I searched about 6-7 other sites like this and finally tried this solution out and I am literally bout to ejaculate on my girl right now b/c everything went smoothly i had no errors anywhere and i’m simultaneously downloading 5torrents at 200-400kb/s a piece and browsing youtube and other sites flawlessly! I am so grateful to everyone’s help and input b/c w/o my torrents I was about to go and hurt someone!
March 6th, 2009 15:52
when the system is infected by malicious virus. VistaTcpPatch is actually the GUI version of the original tcip.sys autopatcher batch script. Patching tcpip.sys is a way to optimize and speed up BitTorrent
March 6th, 2009 14:24
is there a patch for vista tcpip.sys version
6.0.6001.22121?
February 23rd, 2009 05:48
[...] Try this : Windows Vista tcpip.sys Connection Limit Patch for Event ID 4226 My Digital Life #3 Today, 03:18 [...]
February 23rd, 2009 05:02
[...] permalink Try this : Windows Vista tcpip.sys Connection Limit Patch for Event ID 4226 My Digital Life [...]
January 26th, 2009 19:24
[...] just did this to get more incomplete network connections per second depending on the type of vista you use it [...]
January 23rd, 2009 23:11
[...] Tcpip.sys on Windows Vista Follow the article here: http://www.mydigitallife.info/2007/04/09/windows-vista-tcpipsys-connection-limit-patch-for-event-id-… (Sorry I’m not familiar with [...]
December 31st, 2008 01:25
[...] explained before, Microsoft started to implement a upper-bound limit on number of simultaneous half open outgoing [...]
December 31st, 2008 01:20
[...] when the system is infected by malicious virus. VistaTcpPatch is actually the GUI version of the original tcip.sys autopatcher batch script. Patching tcpip.sys is a way to optimize and speed up upload download transfer speed of BitTorrent [...]
December 23rd, 2008 09:17
[...] limitation. Try these instructions: Optimize Vista for BitTorrent, eMule, P2PTV | TorrentFreak Windows Vista tcpip.sys Connection Limit Patch for Event ID 4226 My Digital Life [...]
December 19th, 2008 09:20
Guys Vista SP1 patches this hack. This only applies to pre-SP1 Vista. So you can either decide to uninstall SP1, get a copy of XP, or don’t use this hack until an updated SP1-compatible work-around surfaces. I’m leaning toward the XP route… tired of Vista’s antics.
December 16th, 2008 11:07
Guys DO NOT ATTEMPT THIS IN VISTA.. IT BSODs your Vista and gives a F4 stop error. I had to run the windows system restore function to get back in.
December 10th, 2008 06:16
Vista SP1 notes:
dropped the modded tcpip.sys file and changed registry setting. after a reboot, I get a blue screen.
blue screen didn’t last long enough to capture error code. Also nothing logged in Event Log (lame Microsoft)
My guess is this hack isn’t ready for Vista SP1. It might work for pre-SP1.
Good luck.
December 3rd, 2008 06:25
i tried to follow this now my vistas screwed and when open if it manages to open the mouse doesnt move and it freezes.
My comp works on safe mode but i want to undo all i have done
can anyone please help
November 29th, 2008 22:48
I’ve done everything by this instructions and my Vista collapsed. I’m on XP now, so if anyone has a same problem, let me know. I’ve tried to modify that tcpip.sys file given on site, but I can’t even copy it. What’s the deal?