A Windows 10 1903 update designed to fix Visual Basic issues has caused more issues. Reddit users are reporting that KB451294, which launched last week, is causing increased CPU usage.
The issue appears to be related to SearchUI.exe, a Cortana-related process that is using up to 90% of the CPU for some users. It’s unclear how many users this affects, but reports so far aren’t widespread. Some who have the problem say making changes to Cortana via registry or Group Policy resolves the issue.
Another option is to simply uninstall the update. As Windows Latest points out, this issue was reported by Insiders on the Feedback Hub before it rolled out to masses. It’s unfortunate that Microsoft did not manage to look into the issue before its launch, but here we are.
How to Fix SearchUI.exe CPU Usage
As mentioned, the most foolproof way to fix the issue is to uninstall KB451294. You can do this via the ‘Uninstall updates’ option under ‘View update history’. You’ll be losing fixes for spatial audio, Remote Desktop, and more, but it could be worth it.
If you want to keep the fixes without rolling back, reports suggest registry tweaks are the way to go. Obviously, fiddling around in the registry can cause issues if you aren’t careful, so be sure to make a backup.
Press Windows+R and type regedit.exe. In the search bar, navigate to ‘Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search’. You can set the Reg Value for BingSearchEnabled 0. Delete the key, but be aware this will mean all local search queries are sent to Bing.
Instead, you may have luck replacing your Cortana cache with one from an older build. User falcon4fun from the Windows Ten forums has shared his from 362.295. You can replace the one in ‘C:\Windows\SystemApps\Microsoft.Windows.Cortana_cw5n1h2txyewy\cache\’ with his. With hope, Microsoft will soon roll out a fix that will make these workarounds unnecessary.