Microsoft has acknowledged reports from a "small number of users" who say their PCs are exhibiting CPU spikes when using Windows Desktop Search. A fix is in the works, and should be available in mid-September, the company says.
A recent Windows 10 update is to blame, specifically KB4512941, which Microsoft pushed out to PCs on Friday, August 30. Somewhat ironically, the update was supposed to fix a Visual Basic issue introduced by a previous update. Now a fix is needed for the fix that was supposed to fix a previous fix (that's a Yo Dawg meme in the making).
According to ZDNet, some users affected by the current issue are seeing CPU usage spike to 30-40 percent, and even 100 percent in some cases, when performing a search. Some users have also reported a busted search experience altogether.
"Microsoft is getting reports that a small number of users may not receive results when using Windows Desktop Search and may see high CPU usage from SearchUI.exe. This issue only occurs on devices that have disabled searching the web using Windows Desktop Search," Microsoft states.
"We are working on a resolution and estimate a solution will be available in mid-September," Microsoft adds.
According to Microsoft, this only happens on Windows 10 version 1903 devices in which searching the web from Windows Desktop Search has been disabled. In other words, there's a bug with Microsoft's Cortana integration, which SearchUI.exe relates to.
If you are affected by this, you can hang back and wait for a fix. Alternatively, you can roll back the problematic cumulative update. To do this, head to Settings > Update and Security > Windows Update and click on View update history. Next, click on Uninstall updates, then select Update for Microsoft Windows (KB4512941) and click on Uninstall. You will to restart your PC when doing this.