Windows 10 users complain about high CPU consumption by Cortana after update

A new update of Windows 10 causes high CPU consumption for some users. The bug seems to be in Cortana and the search function of the operating system, among other things. It also appears that Microsoft could have been aware of the issues.

The problem is in update KB4512941, an update to v1903 of Windows 10 that was released to users a few days ago. On Reddit and other forums, users are complaining that their processor consumption is suddenly very high. Screenshots taken by users of their Task Manager show that the problem appears to be in Cortana and SearchUI.exe.

Cortana and the search function consume up to 40 percent of the processing power in some cases. It seems that’s mostly what happens when users disable local searches from being sent to Bing. Disabling that usually has to be done via the registry, so it is not clear how large the group of users is that is affected by the problem. Some users note that replacing the Cortana cache folder with an earlier cache from C:Windows.old can resolve the issue. In that case, however, the local search function may no longer work properly.

Strikingly, it looks like Microsoft could have been aware of the issue. In beta builds of the version of Windows, users already noticed through the Feedback Hub that there were CPU issues in the update. It is not the first time that Microsoft has sent an update to users that has already been complained about in the Feedback Hub. That also happened in October 2018, when users lost data when upgrading to the October Update. Even then, several users warned about the problem. On the current update page, Microsoft writes that there are “no known problems” in this update.