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
Entries (RSS)
November 19th, 2008 00:01
Gloom&Doom, that’s expected if you attempt to use a self-signed version of tcpip.sys in order to avoid having to hit F8 every time you boot. Somehow, you must have gone down that road.
You can either use a normal, unsigned version of patched TCPIP.SYS (the kind in the files at YaronMaor’s link above) along with a boot menu key stuffer called ReadyDriver Plus V1.1 (Google it), or you can continue with the signed version of the file you have, but you’ll need to also do this, which can be tricky:
http://www.mydigitallife.info/2006/11/23/remove-and-disable-windows-vista-evaluation-watermark-from-desktop
Note that Step #10 at that link is incomplete. See line 738? That “Test Mode” needs to be converted like all the others you’ve done. If you don’t, you’ll still have four watermarks on the screen.
November 18th, 2008 17:19
It Works but whenever I use the patch Vista displays Test Mode watermark in all 4 corners of screen. When I restore original tcpip the Test Mode warnings disappear.
November 12th, 2008 14:17
[...] Maylar, you may find this page useful: Windows Vista tcpip.sys Connection Limit Patch for Event ID 4226 My Digital Life [...]
November 11th, 2008 03:32
Simon, um, that’s completely wrong. I know this is the Internet and all, but really, try to get your facts straight.
Visitor, yes, since SP1 MS has boot-time driver signature checking. It’s not only common but expected on all SP1 systems, even x32. If you don’t want to have to bypass it manually every time you boot (using the F8 key), then read up the thread for a couple different alternatives.
November 11th, 2008 03:17
Do you know why this patch doesn’t work anymore?
BECAUSE THIS PATCH IS A YEAR OLD – IT WON’T WORK ANYMORE MICROSOFT HAVE FIXED THIS SO WE CAN’T CHANGE IT.
November 9th, 2008 16:36
Hi fellows, I used the patch and I couldn
t boot the system afterwards. The reason is that during boot a msg about digital signature precented the start. Is this error common?
October 31st, 2008 04:05
[...] Posted by Lukeatluke This is how i solve my(your) problem. Thank you, I’m going to test this tonight. [...]
October 31st, 2008 02:46
[...] is how i solve my(your) problem. __________________ [...]
October 28th, 2008 17:08
[...] Ich habe ebenfalls versucht die maximalen Verbindungen nach folgender Anleitung anzuheben. Windows Vista tcpip.sys Connection Limit Patch for Event ID 4226 My Digital Life Aber auch dies blieb ohne Erfolg. Nun bin ich ratlos und vorallem genervt von st
October 12th, 2008 09:04
I usually set uTorrent to 75 or 100, which should be more than it would use. This is well under the limit you set in Windows when doing the patch.
October 12th, 2008 07:43
So what should I set to net.max_halfopen in the uTorrent settings after I have installed the patch? Now it is set to 4. Should I even change it?? i am using vista home basic.
October 8th, 2008 11:56
awwww., i also got the BLUE SCREEN OF DEATH!!! i just replaced the file and then restarted,m then boom., i can’t even open windows., awww., what the hell., now i know why vista sucs., any solutions?
October 7th, 2008 14:50
Got the blue screen of death, ran windows repair once now and it hasn’t fixed anything. If anyone fixes this keep us updated, going to bed, too late to wait 20 minutes for the vista install cd to load again.
September 27th, 2008 17:57
[...] http://www.mydigitallife.info/2007/04/09/windows-vista-tcpipsys-connection-limit-patch-for-event-id-... [...]
September 25th, 2008 17:23
[...] Windows vista [...]
September 4th, 2008 22:08
[...] (patch) – Home and follow the instructions. For those of you that want more information about it: Windows Vista tcpip.sys Connection Limit Patch for Event ID 4226
August 28th, 2008 22:22
Chris, and what version were you using exactly? You mentioned you were on SP1, so depending on the version of your TCPIP.SYS, you should have been using v2.1a or v2.2 (see post #304 for details).
It pays to read the comments, as you can’t use old versions. They’re proven good files, obviously.
And be sure the read the Readme for special info having to do with the boot manager, else it will appear that you have BSOD’d even with the correct version.
August 28th, 2008 17:35
BLUE SCREEN OF DEATH!!!! immediately at startup. finally figured out it was to do with the tcpip.sys being corrupt. beware of using this. leave your connection alone unless you feel like reinstalling windows.
August 24th, 2008 15:58
i have vista sp1 x32 and when i used tyhis patch i had 2 system restore it . it would not let me boot. i got blue screen of death do not use
August 23rd, 2008 23:50
Installed the half-open patcher (see previous post) and it works smoothely, no fuss to install, easy GUI, set the nummber of half-connection, reboot, and you are done. Rollback to original tcpip.sys is possible.
August 11th, 2008 00:08
Thank you much for the patcher.
August 10th, 2008 03:06
I was thinking more along the lines of a security program of some kind which operates on file signatures, particularly for files in important directories like that one. Once it saw that the file was no longer the one it knew, it locked access to that file, though it certainly should have notified you about it.
I don’t know if the program you use does that, however.
Tons of people have used the patched file without incident. It can’t behave differently for you than others without some other variable involved.
Checking the System log for that time period might be informative.
Did you install using the batch file? Because that should have plowed right through any locked file issues.
August 9th, 2008 23:11
It looked to me like the system has recognized the new file and didn’t want to accept it. No firewall could be blocking it, because I didn’t change any settings for it. I just replaced the tcpip.sys (after some trouble-at first the file was locked, and I have some trouble removing it).
August 8th, 2008 04:47
Since the file itself (tcpip.sys) is good, it sounds to me like a firewall (or comparable) program was blocking or otherwise interfering with communications, as it didn’t recognize the new system file.
August 8th, 2008 04:38
My problem wa this: after applying this “home made” patch, all my external connections have failed, LAN and Wireless. After waiting about 30 mins for something to happen, nothing did. So i copied back original file and rebooted the system. Before login wireless hass connected, after login I can access my home network (LAN). So this patch doesn’t work for me.
Yes, I checked for the right version of the file, I installed that readydriver (or whatever it is) for quicker boot, but it didn’t work. Looks like I will have to live with this stupid enforcment until official microsoft update (that will happen: never).