In June Microsoft rolled out cumulative update KB4559309, which brought the new Chromium-powered Edge browser to Windows 10 users, replacing the old EdgeHTML Edge.
Unfortunately, after delivering a faster browser, the update also appeared to slow down Windows 10, with users complaining of performance issues, with slow boot times, slow loading of apps and ever web pages loading slowly.
Now, on Microsoft Answers, a moderator has finally confirmed that Microsoft Edge team is currently in the process of investigating this problem.
An easy fix for Cumulative Update issues is normally to simply to uninstall them, but in this case, the uninstall process will fail. It seems the only way to get rid of KB4559309 is to do a System Restore.
If you have not received KB4559309 yet, you can ironically avoid it by simply downloading the new Edge browser, which will block the install.