What Is “Windows Modules Installer Worker” and Why Is It Running on My PC?

If you hear your computer’s fans spin up and feel it getting hotter for no apparent reason, check the Task Manager and you might see “Windows Modules Installer Worker” using a lot of CPU and disk resources. This process, also known as TiWorker.exe, is a part of the Windows operating system.

This article is part of our ongoing series explaining various processes found in Task Manager, like Runtime Brokersvchost.exedwm.exectfmon.exerundll32.exeAdobe_Updater.exe, and many others. Don’t know what those services are? Better start reading!

What Is Windows Modules Installer Worker?

This system process “enables installation, modification, and removal of Windows updates and optional components”, according to its service description.

Windows 10 automatically installs operating system updates via Windows Update, so this process is likely just installing updates in the background. However, if you choose to uninstall an update or add or remove an optional Windows feature, the Windows Modules Installer Worker process will also need to do some work.

While the process is named Windows Modules Installer Worker on the normal Processes tab in Windows 10’s Task Manager, its file name is TiWorker.exe, and you’ll see that displayed on the Details tab.

Microsoft releases updates on “Patch Tuesday”, the second Tuesday of every month. They may also release updates on other days, if necessary. If this process is using a lot of CPU, it’s likely that your computer has just downloaded new updates from Microsoft.

You may or may not have to restart your computer to install these updates, but Windows does a lot of updating work in the background so you can continue using your PC while it installs the updates.

Why Is It Using So Much CPU?

Here’s the bad news: As far as we can tell, occasional high CPU usage from the Windows Modules Installer Worker process on Windows 10 is just normal.

The good news is that, if you allow it to run, the process will eventually finish and stop using CPU and disk resources. The Windows Modules Installer worker process will finish and it will disappear from the running processes in Task Manager. How long it will take depends on the speed of your computer’s CPU and storage, as well as on how many updates it needed to install.

Can I Disable It?

You’ll see some bad advice online recommending you should disable the Windows Modules Installer system service to prevent this from happening. This will prevent Windows from installing updates properly, and you shouldn’t do it.

Similarly, others may recommend setting your network connection to “metered”, which will prevent Windows 10 from automatically downloading and install many updates. This will prevent the Windows Modules Installer process from activating, but your computer won’t install critical security updates that can protect you from malware like the WannaCry ransomware, which exploited a bug patched two months before it was released. Avoiding operating system updates is dangerous, and we don’t recommend it.

Sure, you could install updates manually—but the Windows Modules Installer Worker process will run after a manual update, anyway. It’s probably best to just bite the bullet and allow the TiWorker.exe process to occasionally do its thing. This is just how Windows installs updates, and it’s for your own good.

Is It a Virus?

This process is a part of Windows itself. We haven’t seen any reports of malware disguising itself as the Windows Modules Installer Worker, or TiWorker.exe process. However, if you’re concerned about malware, it’s always a good idea to run a scan with your preferred antivirus program to check if anything’s amiss.

If You Think Something’s Wrong

If you think something’s really wrong—perhaps the Windows Modules Installer Worker process has been churning away for hours, or perhaps you think it just runs too frequently—there are some troubleshooting steps you can take. These won’t help if the process is just running for normal reasons, but can potentially fix problems with Windows Update and the Windows operating system itself that could cause issues with the Windows Modules Installer Worker service.

The Windows Update troubleshooter can find and fix problems with Windows Update that could cause issues to occur. To run it on Windows 10, head to Settings > Update & security > Troubleshoot > Windows Update > Run the troubleshooter. Apply any fixes the troubleshooter suggests.

If the troubleshooter doesn’t help, you may want to try using the SFC or DISM tools to scan your computer for corrupted or missing system files.

You may also want to check out our tutorial on what to do if Windows Update gets stuck, to ensure Windows Update is running properly.

And, if all else fails, you can always try resetting your PC to its default factory state and starting over with a fresh operating system.

Chris Hoffman is a technology writer and all-around computer geek. He's as at home using the Linux terminal as he is digging into the Windows registry. Connect with him on Google+.