BSOD WIN 8.1U1 0xc000021 [M953]

[ol]- Summary: Blue Screen after installing CIS in WIN 8.1U1 on AMD Processor

  • Can U reproduce the problem & if so how reliably?:
    Happen every time reboot or reinstall.
  • If U can, exact steps to reproduce. If not, exactly what U did & what happened:
    1: Have WIN 8.1U1 on AMD A6-4400M APU
    2: Install CIS. Restart. Wait a few mins by navigating through Windows explorer/type a document in notepad.
    3: Crash to Blue Screen with error code 0xc000021
  • If not obvious, what U expected to happen:
    Try playing a game, the crash happens when you try to log into the store.
  • If a software compatibility problem have you tried the conflict FAQ?:
    Not compatible with WIN 8.1U1? Well then, that’s a shame to COMODO.
  • Any software except CIS/OS involved? If so - name, & exact version:
    Microsoft Windows
    Comodo Dragon
    Comodo Ice Dragon
  • Any other information, eg your guess at the cause, how U tried to fix it etc:
    Error in winlogon.exe from msgina.dll. CIS inserts an invalid msgina.dll.
    A Complete Dump File can be downloaded from here:

[ol]- Exact CIS version & configuration:
Comodo Internet Security 7.0.315459.4132

  • Modules enabled & level. D+/HIPS, Autosandbox/BBlocker, Firewall, & AV:
    Realtime Protection: Stateful
    Defence +: Disabled
    Autosandbox: Partially Limited
    Firewall: Safe Mode
    Cloud Lookup: Enabled
    Send usage statistics to help improve Comodo: Enabled
  • Have U made any other changes to the default config? (egs here.):
    No. Installed with default configuration
  • Have U updated (without uninstall) from CIS 5 or CIS6?:
    [li]if so, have U tried a a clean reinstall - if not please do?:
    [/li]- Have U imported a config from a previous version of CIS:
    [li]if so, have U tried a standard config - if not please do:
    [/li]- OS version, SP, 32/64 bit, UAC setting, account type, V.Machine used:
    Win 8.1 Update 1 x64,
    UAC on,
    HP g6 2123US,
    AMD A6-4400M APU [at]2.7-3.2GHz
    8GB DDR3 RAM [at]1600Mhz
    512MB AMD Radeon HD 7520g [at]800Mhz
    640GB SATA HDD
    Intel® Centrino® Advanced-N + WiMAX 6250
  • Other security/s’box software a) currently installed b) installed since OS, including initial trial security software included with system:
    None. CIS is the first thing I install on my OS. Did a fresh install of WIN8.1, Did all updates, installed the U1 msu packs, rebooted twice, then installed CIS the next day.

You do not need to purchase the the full version of CIS Pro in order to solve this. What the representative probably meant was that they could not try to fix this for you unless you purchased the subscription. However, I can tell you that you would find the same problem with that version.

As for this report, I can tell you that it is very well filled out. The first thing I would like for you to do is to see if reinstalling it by following the advice I give in this post is able to solve this issue. Please let me know if the same issue occurs even after reinstalling by following those methods. If it does then let me know and we can continue diagnosing this issue.

Thank you.

Thank you for a speedy reply Sir :-TU

I will follow the procedure you mentioned and let you know if it happens again. I have previously tried to reinstall with the same result. Hopefully this time i can use another laptop to report the crashes.

Thanks. If you have not already tried reinstalling with running the removal tool it may have different results. Let me know what you find.

Mr. Chiron,

I have download and installed successfully. While the extremely large signature database is updated I can report my progress.

First I downloaded via the link you supplied.

Then I installed:

Then it automatically did this:

Now it scans:

Scan has finished:

Now I shall reboot and see if I BSOD again:

Okay, all of that seems correct. Let me know if the BSOD occurs.


First it shutdowns all other processes:

Then it BlueScreens

Honestly, I can’t take this anymore. It works for 5 mins, then shutdowns all other processes, then blue screens. If anyone has win 8.1U1 DO NOT install Comodo Internet Security!!

The following steps restored my computer completely to fast working order:

Just a little background info: this laptop belongs to my girlfriend. I am the IT Admin for a fairly large company (which i cannot disclose for privacy reasons. I recommended and made the company purchase and installed Comodo PRO security on ALL of our company’s computers and laptops. They rich, they can afford it. I even installed to my girlfriend’s laptop (bragging how good CIS was)

Thank you COMODO for giving me all this work now. Now i have to uninstall from EVERYONE’s computer before it makes them BSOD with the U1 update on the 8th of this month. I got it early from MSDN for testing purposes. Additionally, I am embarrased to report this to the Board of Directors :embarassed: After I recommended COMODO so highly… :cry:

Okay. In that case this looks like a bug which probably cannot be fixed except by the devs. Therefore, I will direct you towards the information which must be collected, and how to collect it. Once that is done, and this report is submitted, I can direct you to where you can find the previous version. That way you can use it without worrying about a BSOD.

  1. Please first configure your computer so that it will create a Complete Memory Dump. Instructions on how to do that are given here.

  2. Then replicate the BSOD.

  3. After the computer restarts navigate to the newly created Complete Memory Dump (it will be huge) and upload it to a file sharing site. The best one I have found is Mega (found here). It will require you to create a Free Account to share the download link (once it finishes uploading), but I believe it is worth it. [note that if need be this uploading part can be done while the computer is running with a different version)

  4. Once it is uploaded (which may take a very long time), you can respond to this post and paste the download link for the dump. At that point I will have enough information to forward this to the devs.

Let me know if you have any questions, or run into problems.

Thank you.

As you are having serious problems, please create the Complete Dump. Then immediately uninstall this version. After that you can go to this site. Then go to Old Versions and select the last version which worked correctly for you. You can install that one and upload the Complete Dump with that version without worrying about a BSOD.

Now I don’t mind the upload. I have a 60MBS upload speed. I can get it to you in a very short time. What I am annoyed at is how COMODO DOESN’T TEST THEIR ■■■■ PRODUCTS BEFORE SHIPPING IT OUT!! Now I have to BSOD my laptop to help them~!!!

GOD!! the only reason I’ll do it is because the full version of CIS is free!! Wait lemme reinstall…

Update: Hold on. This laptop has been creating FULL DUMPS this whole time. I enabled this setting a while ago.

Here is the Full Dump you requested: [size= 466.5MB]

I’m very sorry that this happened with your machine. This version was tested extensively, and even the Beta had very few problems such as this. I suppose this is likely just bad luck. However, I will now forward this to the devs. Hopefully they will be able to fix this issue by the next update. If you have any further questions please feel free to ask.

Thank you very much for your report in standard format, with all information supplied. The care you have taken is much appreciated by Comodo, and will increase the likelihood that this bug can be fixed.

Developers may or may not communicate with you in the forum or by PM/IM, depending on time availability and need. Because you have supplied complete information they may be able to replicate and fix the bug without doing so.

Many thanks again.

:slight_smile: wow, someone actually did something about this and not just another thread in a forum. I really feel like my voice is being heard and someone is doing something about it! :slight_smile:

I just wanna apologize for raging, but you understand the frustration of having your system crash, right? Now that I see someone will actually do something about this, I feel empowered to help!

I already know what’s most likely wrong. It’s in my first post. CIS replaced a faulty msgina.dll.

Microsoft already knows what causes this error:

I would appreciate it if the Devs read that article. If i had the source code for CIS I would have fixed it myself. I’m a software programmer as well.

The STOP 0xC000021A error occurs when either Winlogon.exe or Csrss.exe fails. When the Windows NT kernel detects that either of these processes has stopped, it stops the system and raises the STOP 0xC000021A error. This error may have several causes. Among them are the following: 1. Mismatched system files have been installed. 2. A Service Pack installation has failed. 3. A backup program that is used to restore a hard disk did not correctly restore files that may have been in use. 4. An incompatible third-party program has been installed.

If I have got this right, software creators are supposed to have their software compatible with OS updates that break 3rd party software compatability before the update is publicly pushed?
That to me seems a little harsh and overly high expectation IMO.
An OS update should not break software, but rather enhance its performance.

I believe that the Complete Dump file should give the devs enough information to trouble-shoot this. If more information is required either they, or myself, will contact you.

I really appreciate you taking the time to report this. This should help others who are experiencing the same issue as well.


You misunderstand me CaptainSticks! What I meant was the the devs should get new OS versions or software updates while they are still in beta, or get the releases early and test the program before users receive the updates. That way, updates for COMODO can be pushed BEFORE users experience problems. For exaple: WIN 8.1U1. Download and install BEFORE users get their hands on a copy of it and test CIS fro crashes and Blue Screens. If any are found, fixes can be made BEFORE damage is done. IE: BetaTesters.

An ounce of prevention is worth more than a pound of cure.

I get software very early and usually have to deal with the crashes :confused: You all should make me a BetaTester :wink:

Fair enough. :slight_smile:
I don’t know the Devs very possibly maybe already doing this.



I’ve just installed Windows 8.1 Update 1 via the normal Windows Update channel. I took a disk image before I started, given the problems being reported, but the update (there were several updates installed) was installed perfectly normally and everything worked well after the reboot. I took no special precautions and applied the update with CIS running just as I would for a normal update.

I was immediately offered a second update (a single update - KB2933809) after the reboot, so I took another disk image and then installed that. Again everything went normally and everything appears to be working normally after the reboot.

I’m running CIS 7.0.315459.4132 and Windows 8.1 was up to date at the time of running today’s updates.

No BSOD here, but I appreciate the warning. :slight_smile:

Understanding some patches from using the MSDN version have been changed before being released as a Windows update.
Bug fixes required to a pre-release update could have a roll on affect causing other unforeseen issues.

This needs to be retested with the released version of update 1 IMO.