After a brief stint in the Release Preview ring of the Insider Program, Microsoft released Windows 10 1903 build 18362.329 (KB4512941) to the production ring – albeit as an optional update. Though the update packages were the same for the builds that were released to the Release Preview ring, only the package for the May 2019 Update was released to production, since 19H2 is still in testing. However, as it turns out, though the cumulative update fixed a bunch of issues, some users aren’t having a great experience.
Users on Reddit began reporting that after installing the latest cumulative update, CPU usage shot up to high numbers even when the system was idle and wasn’t being used. Most users that reported this performance issue noticed that the high CPU usage came from Cortana (specifically the SearchUI.exe process as spotted in the Task Manager). Additionally, the Search functionality in the Taskbar too seems to have become non-functional for those that have hit this issue, with the search flyout turning blank when clicked on.
Interestingly, a few Insiders did log feedback about this issue in the Feedback Hub. However, since the build was not offered to Insiders for long enough before it went out to production, it seems the problem has slipped through. To add to it, the issue did not gather enough upvotes to gain attention. One would expect that the company would wait to gather more feedback for builds in the Insider Preview to be able to better address any such issues.
Microsoft has not officially acknowledged the bug yet. The KB article for this build did not list any known issues with the build either. While there are a few workarounds for fixing this problem such as tweaking certain registry entries, we recommend that you do so only if you are familiar with editing registry keys. Accidentally deleting or editing the wrong registry entries might lead to further issues.
Alternatively, Windows 10 Pro users can head to Settings -> Windows Update -> View Update History and uninstall the troublesome update. For those that haven’t installed the update yet, it is best to not do so. The next cumulative update should contain fixes from this build and should hopefully also fix the performance issues caused by Cortana. Whether the issues will indeed be fixed before the next round of Patch Tuesday updates is anybody’s guess.
Recent updates, in general, have been troublesome for Microsoft, with latest Surface Pro 6 and Book 2 firmware updates too causing CPU throttling issues. These hiccups are sure embarrassing, as the company explained its renewed emphasis on quality after the Windows 10 October 2018 Update debacle.