Windows Modulus Installer Worker Process high CPU Usage and Slows Down Windows 8.1

Let’s troubleshoot Windows 8.1 computer freezing problem due to the Windows Modulus Installer Worker process consuming CPU and in the process slowing down computer. In worst scenarios the computer may become useless to work with, inspite of several reboots and all Windows 8.1 updates installed.

So what is this Windows Modulus Installer Worker process? This process is related to Windows update process and its job to look for updates that are installed on your computer and then prepare your computer for more updates. But sometimes the Windows updates order may get messed up even though you have configured it to download and install Windows updates automatically. You can see the Windows Modulus Installer Worker process in Task Manager. For instance in our test PC, this process is constantly consuming around 15% of CPU and almost 100% of disk speed usage.

Windows Modulus Installer Worker Process in Task Manager

Windows Modulus Installer Worker Process in Task Manager

Now that you know what the process is all about, let’s fix it. Note that this solution should only be applied to computers running on Windows 8.1 or Windows RT 8.1. Before proceeding make sure to log into Windows with Administrator rights.


STEP 1: Download Windows Update Troubleshooter

STEP 2: Run the tool WindowsUpdateDiagnostic.diagcab

STEP 3: Windows update tool will check all the modules related to Windows update including registry keys.

Windows Update Troubleshooter

Windows Update Troubleshooter

STEP 4: The process will take sometime, so you need to be patient until it gives a final report. On our test PC, the tool fixed 3 major problems: Service registration, Windows Update error 0x80073712, and problems installing recent updates.

Windows Update Tool Fix Report

Windows Update Tool Fix Report

STEP 5: Click on Close button and restart your computer.

That’s it, your computer should now perform normally. If not, it is possible that the tool didn’t fix everything in first attempt. So it is wise to run the tool once again and then restart computer again.

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Kiran Kumar

Hi there! Kiran Kumar is an Engineer by profession, and loves blogging primarily on Microsoft Windows operating system and also enjoys reviewing software and products. Currently, he is exploring Windows 10 and you will see a lot of articles on know-how about it. When he is not writing for TWP, he enjoys time with his Family, listens to lot of music, enjoys Biking, and occasionally plays racing games on Xbox One.

  • minky93

    many thanks! sorted out my problems.. cheers!

    • Kiran Kumar

      Glad that it helped you. Thanks for leaving your feedback.

  • tommi_p

    I have been looking everywhere for a _working_ solution for this isssu. Cheers!