Win10 Search, High CPU Lag Plague Latest Update

John Lister's picture

The latest Windows 10 update (KB4512941) has produced two different problems. Some users report the search function is no longer working, while others have found their processors under immense strain.

The problems stem from an update which itself fixed several problems with a major Windows 10 Update release in May, also known as Windows 10 version 1903. Note that users who do not have Windows 10 version 1903 won't have KB4512941 installed. You can find out which version of Windows 10 you have by clicking Start, then type in "winver" (no quotes) and hit enter. It will say the version number followed by the build.

The first problem with KB4512941 involves the built-in search tool in Windows 10 that lets users search across all files on their computer. Although the search box is still available in the Taskbar at the bottom of the screen, affected users no longer get a window showing search results. Instead, they simply get an unresponsive black box displayed.

Windows 10 CPU Persistently High

The other problem is that some users are finding their CPU use persistently high. When they look at the Task Manager for details, they find the Cortana voice assistant tool is listed as using around 40 percent of the CPU.

This consistently high processor use can lead to devices heating up, sluggish processing, fans running consistently and mobile device batteries draining quickly. In this specific case, some users are reporting a drop in frame rate as their computer struggles to keep up with refreshing the screen, resulting in glitchy animations and video playback.

Technical analysis suggests both problems may result from the same bug, namely that the built-in Windows Search for the computer itself and Microsoft's online Bing search are no longer interacting smoothly. (Source:

Removing Latest Update a Workaround

Microsoft hasn't commented on the problems beyond saying it's investigating the issue and will provide an update later on.

In the meantime, the only solution appears to be manually rolling back the update. To do that, users can click Start, then click the cogwheel (Settings) icon, then choose "Update & Security" followed by "View update history" and then "Uninstall updates." The update to remove is KB4512941.

This is only really worth doing for users who are finding either the search or CPU problems particularly troublesome. KB4512941 does fix some other bugs which may be more problematic. However, this is a "feature update" only, so uninstalling it shouldn't have any security implications. (Source:

What's Your Opinion?

Have you experienced either of these problems? Are they annoying enough to make you uninstall the update? Has the amount of problems with Windows 10 updates surprised you or is it just that the frequent update program draws more attention to them?

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Average: 4.8 (10 votes)


Draq's picture

Unless I'm missing something here, KB4512941 appears to be listed under optional updates, which means users won't get it unless they click download and install when it appears ready under optional updates. optional updates are used to test changes before they're deployed in automatic Patch Tuesday updates.

FreedomisnotCONTROL's picture

One is trying to wake from screen saver it was freezing up. and some other little animation issues. I uninstalled the update primarily if its going to run my processor hard really would like my processor lasting as long as possible. Windows isn't paying for the wear and tear on it so better to just uninstall the update till they fix the issues.

buzzallnight's picture

and Win 10 is just another Win 8

I mean, they gave win 10 away for free

and it still wasn't worth the price!

Does anyone realize that we have other things to do
other than F with our computers all the time?

better to stay with win 7

at least 3rd party anti virus will work.

Tom K's picture

I had this problem. I monitor CPU (and other) usage real-time. After the update, CPU stayed over 25% and often reached 50% and higher. The monitoring shows the application that is burdening the CPU. It was search.

I've been using Process Lasso for many years and never had the need to invoke it's more detailed functions. I used Process Lasso's ability to stop a process I specify from running. I did just that with search. Since I don't use Windows 10 search feature, problem solved.

FreedomisnotCONTROL's picture

Before the update and after the update after waking from sleep or a reboot after I log in I get a complete black screen the only way I found to fix it without restarting is to log out and log back in again. Then i see everything on the screen again.