What Is the “System Interrupts” Process and Why Is It Running on My PC?

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If you ever browse through your Task Manager window, you’ve likely spotted a process named “System interrupts” and then probably ignored it. But if it’s using up your CPU and you’re wondering what you can do about it, we’ve got the answer for you.

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

What Is the “System Interrupts” Process?

System Interrupts is an official part of Windows and, while it does appear as a process in Task Manager, it’s not really a process in the traditional sense. Rather, it’s an aggregate placeholder used to display the system resources used by all the hardware interrupts happening on your PC.

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While a hardware interrupt sounds rude, it’s a normal communication between your hardware (and associated software) and your CPU. Say you start typing something on your keyboard, for example. Rather than have a whole process dedicated just to watching for signals from your keyboard, there’s actually a bit of hardware on your motherboard that handles that kind of monitoring. When it determines that another piece of hardware needs the CPU’s attention, it sends an interrupt signal to the CPU. If it’s a high priority interrupt (as is usually the case with user input), the CPU suspends whatever process it’s working on, deals with the interrupt, and then resumes its previous process.

It all happens lightning fast, and there are typically many, many interrupts going on all the time. In fact, you can see this very thing in action if you like. Fire up Task Manager and scroll down until you see “System interrupts” in the window. Now, open up Notepad and start typing. It won’t affect your “System interrupt” setting dramatically, but you should see it rise by a tenth of a percentage point or so. In our case, it rose from a baseline of 0.1% to 0.3%.

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During the course of normal operations, you might see the CPU usage of “System interrupts” rise as high as 10% briefly before it settles back down to next to nothing.

That’s Great, But Why Is It Using So Much CPU?

If you’re seeing the CPU usage of “System interrupts” rise higher than about 20% and–this is the important part–stay there consistently, then you have a problem. Since it’s representative of hardware interrupts on your PC, a consistently high CPU usage typically means that a piece of hardware or its associated driver is misbehaving. So, how do you troubleshoot the hardware problem? Well, that’s the tricky part.

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Your first step should be restarting your computer. We know you’ve heard this a million times, but it’s still solid advice. Restarting your computer can fix all kinds of weird issues and it’s an easy enough step to take.

If restarting your computer doesn’t cure the CPU usage problem, the next step is to make sure that your computer is up to date. Let Windows Update do its thing so you can be sure you have all the latest Windows and driver updates–at least for drivers Windows is managing. While you’re at it, you’ll need to make sure drivers that Windows Update doesn’t manage are also up to date. You can find instructions for doing both of these things in this guide.

If updating your PC and hardware drivers doesn’t do the trick, then you’re going to have dive in and figure out what specific piece of hardware is causing trouble. Diagnosing all your hardware is a bit beyond the scope of this article, but we do have some helpful guidelines for helping you narrow things down.

Start by disabling your external devices one at a time. We start with external devices mainly because it’s the easiest thing to do and you should mainly focus on external drives and input devices like your keyboard, mouse, webcam, and microphone. Just unplug them one at a time and see if “System interrupts” settles down. If it does, then you know what device to focus on.

Next, move to your internal devices. Obviously, this gets a bit trickier since you can’t just unplug them. But you can disable them in Device Manager. You just want to be careful not to disable any devices critical to keeping your system running, like disk drives or display adapters. Also, don’t disable anything listed under the Computer, Processors, or System Device categories. Instead, focus on things like network adapters, sound cards, and other add-on cards. They are the most likely culprits. Just go one at a time. Disable the device and check out “System interrupts” in Task Manager. If the problem goes away, you’ve identified the problem device. If it doesn’t, re-enable the device and move on to the next one.

There are a couple of other pieces of hardware that can cause this problem and that you won’t be able to test this way. A failing power supply (or laptop battery) can cause a spike in the CPU use of “System interrupts” and so can a failing hard drive. You can test your hard drives with Windows’ built in Check Disk tool or with a good third-party S.M.A.R.T. utility. Unfortunately, the only way to test a power supply for this trouble is to replace it.

If you do identify a device that’s causing trouble, your next step is figuring out whether it’s the device itself or the hardware driver that’s causing the problem. Again, this can be a bit tricky to figure out and will require some trial and error, but we have some guidelines.

  • Try external devices on another computer if you have one available.
  • If your drivers are all up to date and you think the device itself is okay, you can always try rolling back to an earlier driver.
  • Hit up Google or your hardware manufacturer’s web site and see if other people are having similar trouble.
  • Consider updating your BIOS. If you can’t narrow down the trouble, it is possible that the hardware responsible for interpreting interrupts is having trouble. Updating the BIOS can sometimes fix the problem.

Can I Disable It?

No, you can’t disable “System interrupts.” And there’s no good reason to. It’s a vital component for your PC’s performance since it’s used to handle and report on hardware interrupts. Windows won’t even let you temporarily end the task.

Could This Process Be a Virus?

“System interrupts” itself is an official Windows component. It is almost certainly not a virus. In fact, since it’s not an actual process, “System interrupts” doesn’t even have an associated .EXE or .DLL file that runs. This means there’s no way for it to be hijacked by malware directly.

Still, it is possible that a virus is interfering with a particular hardware driver, which in turn could have an impact on “System interrupts.” If you suspect any form of malware, go ahead and scan for viruses using your preferred virus scanner. Better safe than sorry!

Walter Glenn is a long time computer geek and tech writer. Though he's mostly a Windows and gadget guy, he has a fondness for anything tech. You can follow him on Facebook and Twitter.