Trusted Reviews is supported by its audience. If you purchase through links on our site, we may earn a commission. Learn more.

Cortana is becoming your CPU master, chief – patch causes usage spike

Microsoft is investigating an issue relating to a new patch, which appears to be causing high CPU usage – courtesy of Cortana.

The patch causing the issue is KB4512941 and it was introduced in Windows 10 1903 (the May 2019 release of the operating system).

Related: Best smart home devices

According to Windows Latest, Windows 10 users began experiencing the hefty CPU spikes following the optional update last week. Microsoft recognised and responded to the issue via the Windows Update Twitter account:

Following the installation of the patch, some users reported a Cortana CPU usage increase of 30-40%.

Ahead of releasing new patches, Microsoft often tests new releases via the Windows Insider program – acting as a beta test of sorts. The “insiders” reported the issue to the feedback hub several times, but appeared to have not gotten the traction required to initiate changes.

The Windows 10 KB4512941 patch was introduced to fix the broken Windows Sandbox, a black screen issue with Remote Desktop connections and some other bugs.

Related: Best laptop

How to fix the Cortana CPU usage issue

While Microsoft has declared a fix is being worked on, there are some actions you can take if you don’t want to wait.

Deleting a registry key:

  • Open Windows Explorer and enter ‘Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search’
  • Find reg name ‘BingSearchEnabled’
  • Change reg value to 0

Users have reported that this solves the issue – preventing Cortana from sending local search queries to Bing and thus solving the CPU spike.

If you aren’t comfortable messing around with the Registry, you can simply uninstall the update.

Uninstalling the update:

  • Open the Settings app
  • Head to Update & Security
  • Click ‘View update history’
  • Next, click ‘Uninstall updates’
  • Find the update KB4512941 and click Uninstall

Why trust our journalism?

Founded in 2003, Trusted Reviews exists to give our readers thorough, unbiased and independent advice on what to buy.

Today, we have millions of users a month from around the world, and assess more than 1,000 products a year.

author icon

Editorial independence

Editorial independence means being able to give an unbiased verdict about a product or company, with the avoidance of conflicts of interest. To ensure this is possible, every member of the editorial staff follows a clear code of conduct.

author icon

Professional conduct

We also expect our journalists to follow clear ethical standards in their work. Our staff members must strive for honesty and accuracy in everything they do. We follow the IPSO Editors’ code of practice to underpin these standards.