Comodo Firewall & CIS 6.3.x latest version

while using comodo firewall in CIS 6.3.x latest version lot’s of legitimate & regularly used websites & webpages are not opening & after disabling the firewall they are opening & also the browsing & download speeds are getting much slower even on high speed broadband internet connections & latest windows 8/8.1 based 32 bit operating systems & using latest versions of google chrome & firefox browser’s , i am from west bengal ( india ) & my internet connection is broadband internet connection , also comodo firewall & CIS products installs an comodo filtering driver which might be the cause of the above very annoying & serious issue , so it’s a request to the well respected developers & programmers of comodo group to please release an urgent fix & update to completely resolve the above mentioned very very annoying & disturbing issue

I changed unneeded caps to normal case. Eric

I have not heard of a bug like this before. However, I have heard of problems with configuration/compatibility issues which could possibly cause problems such as this.

Therefore, in the hope that this can be solved, I will move this to the HELP section of the forum. If it turns out that there is not an easy fix for this please let me know and I can move this back.

By the way, are you sure that this is not caused by Comodo Secure DNS? Please check your DNS settings and ensure that this occurs even when Comodo DNS is not used.


Please make sure that there are no left overs of previously uninstalled security programs around. Not all uninstallers do a proper job. Left over applications, drivers or services can cause all sort of “interesting effects”.

Try using removal tools for those programs to remove them. Here is a list of removal tools for common av programs: ESET Knowledgebase .

When that doesn’t help try a clean installation following Most Effective Way to Reinstall CIS to Avoid/Fix Problems by my colleague Chiron. It will provide a reliable and clean starting point.

Then see if the problem persists or not.

dear chiron i am not an user of comodo secure dns , it’s problem with the comodo firewall & it’s driver itself

In that case please try following the advice EricJH gave and let us know if anything changes. We’ll see if we can get this working properly for you without having to wait for a bug fix.


dear chiron i have follwed the suggestions but nothing has changed & the consequence is all the same as before lot’s of legitimate websites are not opening using comodo firewall & CIS premium free latest version 6.3.x & also the internet connection is getting slowed down a lot specially browsing & download speeds

Okay, just to make sure, did you uninstall CIS normally, then boot into Safe Mode and run the removal tools? Also, did you ensure that the driver for Comodo was removed before installing the new version? If not then please try this.

If so then please provide some examples of the legitimate websites which are not opening. Also, are there any websites which do open normally?


yaa dear chiron this was one of the websites that wasn’t opening :

& there were some other legitimate websites that were not opening too & as you told i did everything complete uninstall of CIS 6.3.x & all of it’s drivers using revo uninstaller pro which completely removes everything including any traces in the registry & after that i installed CIS 6.3.x again but there were no improvements & positive results at all, the internet & broadband speed & surfing & download speed was lot slower than normal as well as lot’s of legitimate websites were not opening , my firewall settings were set at default factory level settings & safe mode , so i think comodo urgently needs to release an update fix for this issue as quickly as possible

A few things to check to make sure Comodo Firewall’s gone:

  • are the processes mentioned in this post [] running?

  • is the “COMODO Internet Security Firewall Driver” listed in the settings of any of your network adapters?

  • your DNS should be set to something other than Comodo’s. Check is by opening a command prompt and typing “ipconfig /all”. If you’re behind a little NAT router, then that NAT router’s probably your DNS server and it’ll probably have an IP address very similar to the one your PC currently has (probably 192.168.x.x or maybe 10.x.x.x)

Revo uninstaller pro does not always remove all files. Sometimes some are missed, which may be what is happening here. Please try reinstalling once more. This time boot into Safe Mode and run the removal tools I reference. Also, follow the advice given by FwFan to ensure that everything is in fact removed, and that the DNS settings are configured correctly.

Let us know what you find.


to all my friends it’s the issue with the comodo firewall & CIS 6.3.x itself & not with anything else try to understand properly what i said in my previous comments

Sorry Mukunda, I’m trying to follow what you’re saying, but your symptoms are vague - on one hand you say this “Revo” software has absolutely removed every trace fo Comodo from your system, and on the other hand you say Comodo’s still causing problems.

So I figure it’s a good idea to look for obvious traces of Comodo still being there - like one of its processes running or that driver-filter still being attached to a network adapter or your DNS settings. Btw, DNS settings are one of those things that I think would be hard for something like Revo to “remove”.

Are you saying here that when you disable the firewall the speeds are good again or are they still slower?

Your style of writing seems to get in the way of understanding your situation. I think if you limit the length of your sentences to hold one or two thoughts and keep sentences on the short side the process of analysing your problem will be more efficient. Also start a sentence with a capital letter and end with a period rather than making a paragraph long sentence with lot’s of comma’s. Clarity is best served with clearly separated thoughts in not too long sentences.

What do the logs say of comodo? Antivirus, firewall, d+