Issues with Update KB890830 (Windows Malicious Removal Tool)

Windows UpdateMicrosoft has released on patch day (April 11, 2017) also a new version of Windows Malicious Removal Tool (MRT) as update KB890830. It seems that this update is causing serious issues.


Malicious Removal Tool (MRT) is shipped on each patch day to run once and clean systems from malware. On patch day (April 11, 2017) a new version of Malicious Removal Tool (MRT) has been released as update KB890830. I received yesterday some comments within my German blog, indicating trouble with update KB890830.

Update KB890830 blocks other updates

Last night I received also some e-mails from 'another source' (thanks Leon – but sometimes I have to take a nap Zwinkerndes Smiley) reporting issues with update KBb4015550.

I've installed update kb4015550 on another pc and received an mrt.exe – error 0xc0000005,


I've translated the text, because it was written in a foreign language. Update KB4015550 is causing a MRT error 0xc0000005 (Access Violation) during install. MRT obvioudly blocks installing other updates. Leon wrote within a 2nd that he had analyzed other updates (KB890830 and KB4014983) as a source of install conflicts, but at least he found the root cause. He wrote:

I found the cause for mrt.exe error – it was caused by update kb 890830. The odd thing is, that I only use windows defender on my machines.

It seems, that MRT is causing serious trouble. My proposal: Hide update KB890830 in Windows 7/8.1 – and if MRT is already installed, uninstall KB890830 and block this update.

MRT collides with other AV software

Leon pointed out, that update KB890830 is causing also trouble with third party antivirus software. Here are a few links pointing to forum entries with related discussion.


Unable to update windows malicious tool (KB890830) (Norton Forum)
Is Microsoft Windows Malicious Software Removal Tool (KB890830) harmful…
Microsoft Update KB890830 won't be installed unless Avast is turned off

Something went terrible wrong with MRT update this month. Are you also facing trouble with KB890830?

Addendum: A solution

Leon provided me with a fix: Just delete the mrt file in Windows\system32\mrt. The launch Windows Update and hide the April 2016 MRT update. Afterward, restart Windows Update search 3 times again, the updates KB890830 for January, February and March are offered. Let em install – so mrt will work in those older versions.

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11 Responses to Issues with Update KB890830 (Windows Malicious Removal Tool)

  1. Pingback: Born: Microsoft Malicious Software Removal Tool update KB 890830 causing problems @ AskWoody

  2. Brad says:

    After installing the patch Tuesday payload over night on Wed. Apr.11 '17 on Windows 7 Ultimate x64, while running my machine on Wed. night it suddenly blue screened. I tried to restart it several times, but right when it went to start windows it would "black screen of death" sometimes it would show the words "Starting windows" then freeze, but mostly it would freeze before it even got that far. I then tried to start in safe mode and it did. I then restarted and tried "Last Known Good Configuration" and it worked and booted Windows 7 normally. If I would not have tried Last Known Good, my machine would still be bricked. At this point I'm afraid to restart again and I'm looking for some guidance as to which recent updates to uninstall. This was a very strange crash, because even though the screen was totally black, my monitors stated on, as if Windows was running, but it wasn't. I have once again disabled Windows Update, just like I did last year during the GXW fiasco, because the people who are at Microsoft now sadly, are a bunch of idiots who can't be trusted with your computer. I have Avast AV, maybe that's what made my computer feel like it ate something that didn't agree with it.

    • guenni says:

      I haven't installed the latest updates for Win 7/8.1 because it contains code to block further updates for new AMD Ryzen and INTEL Caby Lake CPUs.

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  5. Joseph says:

    I lost my Microsoft wireless mouse on two desktop computers running Windows 10. Restarting the systems cleared the problem. I am not sure but I believe the added KB890830 patch is the culprit.

  6. primate says:

    Microsoft's solution is to uninstall KB890830 & reinstall it fresh. However, it cannot be uninstalled because it does not appear in the list of installed updates, although WinVista history shows that it has installed the same dated publication on top of itself 5 times in the past 2 months. And you can neither uncheck it nor hide it because Windows Update keeps reopening with the item already checked saying it needs to be installed. It would appear that the Malicious Software Removal installer has itself become malware.

    • jameson says:

      no way to uninstall it in w10 fore it's intergrated into the operating system – and if it were that ez like w8.1 or w7 sp1 , then u could uninstall it from the control panel .., but now in w10 – when 890830 goes to update – it downloads just fine & but when it starts to install it fails every time & that causes all the other updates that follow MSRT to fail as they go to install aswell .., microsoft assured me that they had a fix for it & even connected by remote session & fixed it they sd. ! but now again this update is failing & this is a MS issue and until it's fixed or a newer version of w10 is released w/o an intergrated version of MSRT no pc or laptop will be able to update in the future even if a w11 upgrade versions will be affected i think cuz they upgrade from a bad version/copy of w10 ..

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  8. Oliver Winer says:

    Estou,com esta atualização aqui (KB890830),ainda não instalei e nem pretendo estou lendo muitos comentários ruins sobre ela,meu computador deu tela azul eu limpei as memórias vamos ver se este foi o problema.Espero que sim.

  9. Keith Austin says:

    I did a check for updates on 15/02/2019 and saw an update for KB890830 when I let Windows go through the in update/ install mode it hung on "Pending Download" it was not automatically downloading the update but I have my settings to automatically download updates from Microsoft. I re-started my system and went back into Updates and it said it failed and gave me the option to "check for updates" which I did, and it gave me a download button for the KB890830 so I clicked the Download button. It then went to "Getting things ready" and hung on that for 2 days. I restarted the device again and went through the motions again…. I was never able to "Install" the update. I did some research and found a link to download the actual tool from Microsoft. This Link: permitted me to download the MSRT (Malicious Software Removal Tool) and I ran the tool. I then went back into the updates and checked for updates again – Presto, it said I was up to date. MSRT needs to run once, once it has, the system recognises this and the "Update" is removed from the list of updates required. I would like to think Microsoft is aware of this issue and fixes what-ever the problem is/ was and fixes the issues before the next MSRT release.

  10. Hal Antonson says:

    kb890830 update will indeed block other updates until fixed.
    In the system 32 directory, do a dir mrt*. You will find an MRT.exe with 0 length.
    Find a copy on another machine that is the same 32/64 configuration and replace your 0 length .exe. Retry the update. It should work this time. Then check for updates again to get up to date. Since this seems to be a recurring problem, a backup of MRT.exe might be in order.

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