In Windows 10, high CPU usage is often a sign of some background app processing activity. However, a consistent high usage could be sign of a problem, or a bug.

That is exactly what I noticed over past week or so. A constantly high CPU usage for Microsoft Office apps.. including Word, Excel, PowerPoint etc. These apps usually do not take much processing or memory.

I’m using Windows 10 and Microsoft Office 2019 with latest updates installed. My laptop would often heat up and become unresponsive too, especially when using any MS Office apps. When I opened the Task Manager, this is how it looked like:

Microsoft Office Click-to-Run (SxS) CPU usage

Notice the Microsoft Excel, Word and Microsoft Office Click-to-Run (SxS) CPU usage: all taking more than 25% CPU. And total CPU usage is 100%. Power usage is also very high.

What Does Office Click-to-Run (SxS) EXE do?

This service runs in the background. But it usually does not take such high resources. But in this case, even when I had no office app open, this Click-to-Run thing would take about 30% CPU resources. Here is what it’s supposed to do:

Manages resource coordination, background streaming, and system integration of Microsoft Office products and their related updates. This service is required to run during the use of any Microsoft Office program, during initial streaming installation and all subsequent updates.‬

Service Description from MMC

The file path is: C:\Program Files\Common Files\Microsoft Shared\ClickToRun\OfficeClickToRun.exe

Why do you need Office-Click-to-Run Service?

So this service is required, if you want to use any of installed Office applications. This terms out any possibility of disabling this service to fix this issue. The service checks for available software updates and lets you install those.

Here is what I tried. None of these solutions worked. Putting it out there as it might save you time…

  • Restart the computer – As a long time Windows user, this is my first go-to “solution” in almost any case involving Microsoft products. You restart your computer and it starts working fine. Well, not in this case.
  • Disable “Office Click-to-Run” service – Don’t do that! When I disabled the service, none of the office apps would work. I then had to run the service again.
  • Clear the Office cache – A lot of solutions recommended that you clear the Office Cache and it will fix the problem. It might have worked for some Office 2016 users, but it did not work in my case.
  • Uninstall and Install Office again – Uninstalled Office. Restarted the computer. Installed Office again. Same issue again.

How to Fix Microsoft Office Click-to-Run (SxS) High CPU usage

If you have set your connection as “Metered Connection”, turn the “Set as metered connection” to “Off”.



  • Click on your internet connection (in taskbar)
  • Click “Properties” – just below the connection name.
  • Scroll down “Metered connection” settings
  • Turn it off
  • Restart your computer

Before:

After:

Turn Off Metered Connection

After your computer restarts, your Office apps should function normally and not use excessive resources. This is how my Task Manager looks like now:

Important: You can then turn the “Metered connection” “On” again after an hour or so. In that time, Office can check for, and install any updates.

Explanation

To fix the issue, I had to re-read the Office Click-to-Run service description again. Notice the bold words:

Manages resource coordination, background streaming, and system integration of Microsoft Office products and their related updates. This service is required to run during the use of any Microsoft Office program, during initial streaming installation and all subsequent updates.‬

I read “streaming” twice, and “updates” twice. So the app is probably trying to check for, or install updates. But because I had set my internet connection as “Metered Connection”, it’s not able to do so. So it keeps trying and keeps using high resources.

What a mess.

This must be a bug which will probably be get fixed soon. But in the meantime, try this fix and let us know in comments if it works/does not work for you.