Update KB4577586 removes Flash in Windows 8 – 10/Server

[German]Microsoft has released update KB4577586 for Windows on October 27, 2020. The purpose of this update is to provide an option to remove the Adobe Flash Player.


Blog reader Gero has already informed me about the update by mail (thanks for that). Furthermore the topic came to my attention on Twitter and blog-reader EP mentioned it here (thanks).

Background information

Adobe had already announced in July 2017, together with technology partners like Microsoft, that Adobe Flash Player would no longer be supported after December 2020. The decision to discontinue support for Flash Player was made by Adobe due to the lower usage of the technology and the availability of better, more secure options such as HTML5, WebGL and WebAssembly. I mentioned that within the blog post Fake News: Flash is dead? No it's fading out is planned 2020. And Microsoft had outlined the roadmap for phasing out Flash.

  • After December 2020, Microsoft will no longer provide a "Security Update for Adobe Flash Player" for Microsoft Edge Legacy and Internet Explorer 11.
  • From January 2021, Adobe Flash Player will be disabled by default and all versions older than KB4561600 (released in June 2020) will be blocked.
  • Downloadable resources related to Adobe Flash Player hosted on Microsoft websites will no longer be available.

In the fall of 2020, Microsoft will provide an update entitled "Update to remove Adobe Flash Player" through the Microsoft Update Catalog, Windows Update and WSUS that permanently removes Adobe Flash Player as a component from Windows. This update will be offered as optional under Windows Update and WSUS in early 2021 and will be recommended a few months later. Please note that this update will be permanent and cannot be uninstalled. See also my blog post Microsoft: Flash Player will be removable in autumn, support will end in 2021.

Flash-Killer Update KB4577586 is available

As of October 27, 2020, Microsoft has now released the update KB4577586 (Update for the removal of Adobe Flash Player: October 27, 2020), which now offers the possibility to remove the Adobe Flash Player from Windows without third-party software. Currently, this update KB4577586 is available for download in the Microsoft Update Catalog.

All Windows systems starting with Windows 8, which have integrated the Flash Player, will get this update (distributed via WSUS starting 2021). Besides Windows 8.1 and Windows 8 Embedded this includes Windows Server 2012 / R2 as well as Windows Server 2019 and Windows 10.


Windows 10 version 1909 uses the same updates as version 1903, so if you are using Windows 10 version 1909, download the update for Windows 10 version 1903.

For Windows 10 20H2, the update for Windows 10 version 2004 should be used, since it applies to both the 2004 and 20H2 versions.

After installing the update, the Adobe Flash Player is uninstalled/deleted. There are only remnants in WinSxS that partialle are no longer executable. Bleeping Computer wrote, that they was able to enable Flash in Microsoft Edge and other browsers. I then did a search in the WinSxS folders and ran FlashUtil_ActiveX.exe as administrator. I was then offered a dialog box to uninstall the Flash Player. However, the uninstaller does not remove the files in question. Somehow this is not really transparent yet.

Microsoft states that no known issues with the update. But note, that the update can no longer be uninstalled. To get Flash back, you have to use System Restore or reinstall Windows.

Gero writes: I installed the update on a 20H2 machine and the Flash Player was successfully removed. I have also tested this, downloaded and run the update for Windows 10 version 2004, works also on 20H2.

Similar articles:
Fake News: Flash is dead? No it's fading out is planned 2020
Microsoft: Flash in Browser will be removed end of 2020!
Microsoft: Flash Player will be removable in autumn, support will end in 2021

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5 Responses to Update KB4577586 removes Flash in Windows 8 – 10/Server

  1. guenni says:

    I received also feedback in the German blog (see here), that the update could not be installed on Windows Server 2012 R2. Note: Windows Server 2012 R2 has no Flash installed by default. It will be installed when the server feature "Desktop Experience" is installed. Maybe that helps.

    German ex MVP Mark Heitbrink has send me the link to his uninstall batch script at gruppenrichtlinien.de. Probably the better aproach?

  2. EP says:

    hi guenni

    recent report from Bleepingcomputer that a recent Windows Update scan would "force install" the KB4577586 update without user consent under Win10 if the KB4577586 update was not already installed:


    also recently referenced from Askwoody:

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