FIX: Edge Update KB4559309 makes computer very slow.

Last updated on September 19th, 2020

In June 2020, Microsoft has automatic delivered the new Chromium-based version of Microsoft Edge, with the update KB4559309. But many users complain that the automatic installation of Edge Chromium with the update KB4559309, makes the computer very slow and generally affects negatively the computer's performance.


FIX Slow Performance after Edge Update KB4559309


Know issues after installing Edge Chromium (Update KB4559309):

  • Slow boot.
  • Computer is slow at random times.
  • High Memory usage.
  • Wireless Connection is disabled.

This tutorial contains step-by-step instructions to resolve the low performance issues after installing the new Chromium-based version of Microsoft Edge in Windows 10.

How to FIX: Slow Computer Performance after Installing Update KB4559309 and the new Chromium-based version of Edge. *

* Important: If you want to prevent the KB4559309 update to be installed on your PC in order to avoid problems after installing it, do one of the following:

A. Prevent the automatic delivery of Edge Chromium with the KB4559309 update, by following the instructions on this article: How to Block Edge Chromium from Installing Automatically in Windows 10.


B. Download and install manually the new Chromium-based Edge browser,

Method 1. Restore your PC to a Previous Working State.

If you have enabled the System Protection on your PC, then proceed and restore your system to a previous working state. To find out, if the system protection is enabled on your system and to restore your PC:

1. Right-click on This PC icon in Windows Explorer and select Properties.

PC Properties


2. Click System Protection.

System Protection

3. If the system protection in On on Local Disk C:, click the System Restore button. *

* Note: If the system protection is OFF on drive C:, then continue to next method.

System Restore

4. At System Restore options, choose a previous date to restore your system and click Next to restore your PC on the selected date.

Method 2. Disable BitLocker.

If you have BitLocker protection enabled on one of your local drives, proceed and disable it. To do that:

1. Navigate to Windows Control Panel ("small icons" view), and open BitLocker Drive Encryption.

bitlocker drive encryption windows 10

2. If the BitLocker is ON, in one or more drives, then click the Turn off BitLocker option to disable the BitLocker encryption.

Turn Off BitLocker



3. When the decryption process is completed, restart your PC and see if the slow performance issue is fixed.

Method 3. Install Updates KB4568831 & KB4562899.

1. Download and install the following two (2) Windows 10 2004 Updates, from the Microsoft Update Catalog:*

* Note: This method applies only to Windows 10 v2004.

2. After installation, restart your PC and see if the slow performance issues persists.

Method 4. Uninstall the New Microsoft Edge (Chromium Based version).

The final method to resolve the slow performance issues after installing the update KB4559309, is to uninstall the new Microsoft Edge browser. To do that:

1. Go to Start image  > Settings > Apps.
2. In Apps & features
section, locate the Microsoft Edge and click Uninstall. *

Uninstall Microsoft Edge

* Note: If the "Uninstall" option is greyed out, proceed and uninstall the Edge browser from command prompt, by following the steps below:

1. Open Windows Explorer and navigate to the folder: *

  • C:\Program Files (x86)\Microsoft\Edge\Application\85.0.564.41\Installer

* Note: The numbers in red letters is the installed version of the new Edge browser, as the article is written. So, the numbers (version) may be varied according the installed version of Edge on your PC.

2. Highlight the contents in the address bar and press the CTRL + C keys to copy the path on the clipboard.

Uninstall Chromium version of Edge

3. Open Command prompt as Administrator.

4. Now, type CD press the Spacebar key once and then press the CTRL + V keys to paste the copied path and press Enter.


Uninstall Edge Chromium

5. Finally copy and paste the below command and press Enter. *

  • setup.exe –uninstall –system-level –verbose-logging –force-uninstall

* Note: When the command is executed, the old version of Microsoft Edge will return.


6. Finally, proceed and prevent Edge Chromium from re-installing automatically, or download and install manually the new Chromium-based Edge browser to avoid the automatic delivery of it with the KB4559309 update.

That's it! Which method worked for you?
Let me know if this guide has helped you by leaving your comment about your experience. Please like and share this guide to help others.

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