For nearly two years, my PC always sounded like it was under load. The fans spun up within minutes of booting Windows, even when the machine was just sitting idle. I ran malware scans and reinstalled drivers, and worked through every troubleshooting guide I could find. Nothing told me why my CPU stayed that high at idle.

Eventually, I stopped trying to fix it. The computer still worked, so I accepted the fan noise as something I’d have to live with. The fix came later from somewhere I’d never thought to check. I switched browsers because I wanted better privacy, and within days, the CPU problem I’d been chasing for two years was gone.

Chrome wasn’t the suspect

Switching for privacy and finding the real problem

Chrome was the one thing I never thought to check. It was just my browser, not something I’d troubleshoot, and privacy is what brought it into the conversation. Chrome collects your browsing history and location data in the background, and I just didn’t want to deal with that anymore.

Brave is an option, but it still uses Google’s browser engine. If I were moving away from Chrome for privacy reasons, I would want a clean break from that ecosystem. Firefox is the only major browser not built on Chromium. While Mozilla does get most of its revenue from a Google search partnership, it doesn’t monetize your browsing data. So, I moved my bookmarks and passwords over one day. Performance wasn’t on my mind at the time, as I was just trying to get away from Chrome.

Within a few days, the fans had stopped. I opened Task Manager, and the CPU was at 3 percent, and the only difference was the browser. I searched for Chrome-related processes and found it was still active on my machine, but I hadn’t opened it in days. Extension workers were running in the background, along with syncing services and startup boost processes. Chrome loads all of them the moment you sign into Windows.

If you open Chrome’s settings and go into the System section, you’ll find an option that keeps background apps running after you close the browser. It’s turned on by default, and not something you’d stumble on unless you were looking for it. So, whenever I started my PC, Chrome loaded these processes automatically, eating CPU, whether the browser window was open or not.

What no CPU guide ever mentions

A blind spot in every CPU fix

If you search for “high CPU usage at idle,” most guides tell you to stop startup apps and disable background services like SysMain. Some also focus on what’s happening while your browser is open, such as having too many tabs or resource-hungry extensions. What I rarely saw mentioned was checking whether the browser had actually stopped running after I closed it.

In Task Manager, Chrome’s background activity appears as multiple chrome.exe processes. At first, I assumed they were shutting down or left over from my last browsing session, so I ignored them. None of the troubleshooting guides I followed suggested checking whether those processes had actually stopped running after Chrome was closed.

Of course, ending those processes in Task Manager only solves the problem temporarily because they can return after the next reboot. If Startup Boost and background apps are enabled in Chrome’s settings, the browser can start certain processes as soon as you sign into Windows, even if you never open it. So every time I restarted my PC, which was one of the most common fixes I came across, the same Chrome processes came right back.

Removing Chrome and fully switching to Firefox was the only true fix, and, as said, has some pretty nice privacy benefits, too.

The window closed, but the app didn’t

Chrome isn’t the only app that keeps running after you close it. Spotify and Discord do the same thing, and Edge has a similar setting buried in its System menu. So the next time your machine feels sluggish at idle, open Task Manager and sort by CPU usage.

If you notice the same process showing up every time you restart your PC, it’s worth checking that app’s settings to see whether it has background or startup features enabled by default. You might find, like I did, that the problem isn’t Windows at all. It’s the software you assumed had already stopped running.

OS

Windows, macOS, Linux, Android, iOS

Price model

Free

Firefox is a free, open-source web browser developed by Mozilla, focused on speed, privacy, and security for users on all major platforms. It includes advanced features like tabbed browsing, a built-in password manager, private browsing mode, strong tracker blocking, and customization through thousands of extensions and themes.