KB5003173 Cumulative Update for Windows 10 2004 and 20H2

May 2021 cumulative updates are out and you may get this for your computer via the Windows update section. With this security release, Microsoft removes the prerequisite of installing recent SSU first. So, you may now download a single file and the rest will be taken care of. Windows 10 2004 and 20H2 users will receive a cumulative update under the name “KB5003173 “.

Applying this security patch will increase Windows 10 2004 OS Build number to 19041.985, whereas version 20H2 to 19042.985. Let’s explore the key features of this update in detail –

KB5003173 Changelog

Here are the key changes that will occur after applying this security patch on your device –

  • No need to install the servicing stack update separately before applying the latest cumulative update. The company had announced this in earlier patches. Well, this is now applicable for all Windows 10 versions and editions. 
  • Enhances security of the following –
    • Windows App Platform and Frameworks, Windows Media, the Windows Kernel, the Windows Silicon Platform, and the Microsoft Scripting Engine.
  • This update also includes an update for Microsoft HoloLens. Those clients who haven’t updated their HoloLens to the latest OS Build may receive a direct update from Microsoft. 
  • Improves the security of Windows OLE (compound documents).
  • In the end, this Tuesday patch also provides security for Bluetooth drivers.

Known Issues on KB5003173

After applying this security patch, you may encounter one or more of the following issues on your device. So, check first if any bug is going to seriously impact you or not. Only when you are absolutely sure, go ahead and install this cumulative update.

  1. Loss of System and User Certificates
  2. Entering kanji characters won’t transform to enter Furigama characters automatically on the Japanese IME.
  3. Microsoft Legacy Edge will get removed, however, without replacing it with the new Chromium-based Edge. This issue arises only if you had used custom offline media or ISO images to install Windows 10 on your computer. 
  4. After installing the KB5003173 patch, you may get lower performance than expected while playing games on your device. 

How to download and install this patch update

To download and apply the 11th May security patch on your device, use these steps –

Note: As Microsoft has now clubbed both servicing stack and cumulative update together, you are not required to download/install the recent SSU separately. 

  • First of all, visit the Microsoft Update Catalog site.
  • Under the Title section, locate your Windows 10 version. Make sure to download the update that matches your system architecture i.e. x86, x64, or ARM64.
  • Once you have checked all essential details, hit the Download button.


  • Doing so will redirect you to a new window. 
  • Click over the link present on your screen. If there is more than one link, select the top link.
  • Wait for a few minutes while the downloading completes.
  • Once this is over, open the folder containing the setup file, and double-click over it.
  • The installation begins shortly afterward. Your PC may restart several times during the update. 

Release Note

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