PC Fans Running in Sleep Mode? (How To Fix It)

Are your PC fans still running while it’s in sleep mode? Not only is this annoying, but it’s also worrisome. A nonstop PC fan might mean that your hardware is getting too hot, or that there’s a software bug causing the fans to keep spinning.

Here is how to stop PC fans from running in sleep mode:

1. Run the Windows troubleshooter.
2. Disable Modern Standby.
3. Check the System BIOS.
4. Properly configure sleep mode.
5. Scan and fix corrupted files.
6. Troubleshoot by removing recently installed software.
7. Check the Windows Event Viewer.

In this article, I’ll go over each of these points in detail so you can follow along and stop your PC fans from running in sleep mode.

Besides discussing step-by-step guides, I’ll also go over why these fixes work and the potential underlying issues.

I’d suggest that you apply these solutions in order, as we’ll start with the most likely fixes.

1. Run the Windows Troubleshooter

One of the easiest and most straightforward ways to fix problems on Windows is to let the OS do it for you. 

Windows PCs come with a set of tools called the Windows Troubleshooter that can automatically diagnose and fix basic problems in your system. 

Now, since your PC fans are running while Windows is in Sleep Mode, you might have some hardware configuration issues or problems with the Power settings.

As such, I’d recommend that you run the Windows Troubleshooter for Hardware & Devices and Power to cover all potential problems that might be causing the issue.

Here are dedicated step-by-step guides on how to run the troubleshooters on both Windows 10 and Windows 11.

How to run the Windows Troubleshooter on Windows 10

Follow the given steps to run the Windows 10 troubleshooter for your PC fans and the sleep mode:

1. Open Settings (Press Win + I) and navigate to Settings > Update & Security > Troubleshoot.
2. Scroll down to find the option Additional troubleshooters and click on it.
3. Under the Find and fix other problems section, you’ll find the Power troubleshooter. Select it and then click on the Run the troubleshooter option.
4. A new pop-up window will appear starting the Troubleshooter. Give it a few minutes to detect potential problems.
5. Once the Troubleshooter finds an issue, it’ll display what it thinks is out of place and ask you to Apply this fix or Skip this fix. Select Apply this fix.
6. Wait for a few minutes till the Troubleshooter fixes the issue.
7. Once the process is complete, close the Troubleshooter and restart your system.

Next, you’ll need to run the Hardware and Devices troubleshooter. To do that, follow the given steps:

1. Go to Windows Search and type in cmd. The Command Prompt app will show up. Select Run as administrator.
2. In the Command Prompt, type – msdt.exe -id DeviceDiagnostic and press Enter.
3. A new window will show up with the Hardware and Device troubleshooter option. Click on Next to start diagnosing what’s wrong with the PC fans.
4. Follow the on-screen instructions and wait till the troubleshooting process is finished.
5. Once done, restart your PC.

Run the Windows Troubleshooter on Windows 11

With the Windows 11 update, the Settings app has got a major revamp, and none of the options are where they used to be on Windows 10.

Here are the necessary steps to run the power troubleshooter on Windows 11:

1. Press Win + I to open Settings. Then go to System > Troubleshoot > Other troubleshooters.
2. Scroll down. Under the Other section, you find the Power troubleshooter option. Click on the Run button right beside it.
3. A new pop-up dialog box will appear, which will begin the diagnostic process.
4. Follow the on-screen instructions to complete the troubleshooting process.
5. Once complete, restart your PC.

Now, to troubleshoot Hardware and Devices on Windows 11, you can follow the same exact steps we discussed with Windows 10.

After running both Power and Hardware troubleshooters, put your Windows PC to sleep and check if the fans are still running. If yes, then move on to the next step. 

2. Disable Modern Standby

Did you know that Windows has different sleeping states? 

In some sleep states — S0 & S1 — the CPU is still active, which explains why the fans are still on. 

Furthermore, S0, also known as Modern Standby, is becoming more popular.

Modern systems (especially laptops) are configured with S0 as the default sleep state, replacing the traditional S3 sleep state, where the CPU is turned off, and subsequently the CPU fans.

Now, Modern Standby does have benefits. It provides a smooth on-off experience, similar to locking and unlocking your mobile phones.

Unfortunately, it also has drawbacks, including a continuously running CPU fan.

As such, if you own a new PC or laptop, it’s worth checking if Modern Standby is enabled. If yes, I suggest that you disable it and turn on the S3 sleep state instead. 

That said, to change the sleep state settings, you’ll need to head into your system’s BIOS. 

Since the BIOS interface is different for motherboards coming from different manufacturers, I cannot provide an exact walkthrough.

You should be looking for settings related to Power Management and Suspend Mode.

I’d suggest that you check the manual or visit the manufacturer’s website to see how to change sleep state settings.

Also, in some situations, you might find that your motherboard does not support the S3 sleep state. In that case, you’ll need to edit the ACPI table. 

Here’s a detailed guide on how to disable modern standby in Windows that should help you out.

3. Check the System BIOS

Did you know that your System BIOS controls and regulates the fans? 

Most modern BIOS will have settings that let you configure your PC fan’s RPM (Rotations Per Minute) in relation to the internal temperature of your system.

Now, most PCs come with a smart fan mode that increases the fan speed when temperatures are hot and decreases the speed as things cool down.

However, some configurations go for a steady high speed for PC fans regardless of the PC temperature.

As such, if your PC fan is configured to always run at high speeds, then that’s possibly why it’s spinning even when the system is in sleep mode.

Now, to change this, you’ll need to enter the System BIOS, look for Fan Settings, and enable “Smart” or “Auto” fan mode. The interface and specific option names will vary from system to system.

That said, to give you a basic idea of how it works, here’s a quick 8-min YouTube video from Britec09 showcasing how to control the CPU and System fan speeds on an MSI motherboard:

4. Properly Configure Sleep Mode on Your PC

Is your Windows system automatically entering sleep mode after a period of idleness, or are you manually enabling it — by pressing the power button or Sleep button in the Start menu?

If Windows is activating it automatically, how can you be sure that it’s actually enabling sleep mode? 

For example, it’s perfectly plausible that your PC just turned off the display, making you think it’s in sleep mode, but actually, all internal components are active, including the fans. 

As such, I’d recommend that you dive into your Windows settings and properly configure Sleep Mode to the way you want it to function. 

To help you out, here’s a 7-minute YouTube video by the channel Windows, computers and Technology going over the Windows 10 power settings and sleep modes:

On Windows 11, the Settings app got a revamp with a brand new interface. To open the Power Options as shown in the video, you can follow these steps:

1. Go to Search, type in Control Panel, and open the Control Panel app.
2. Set View by to Large icons.
3. Locate the Power Options and click it.

From here, you get the same interface and options as shown in the video.

5. Scan for Corrupted Files or Viruses

Are you facing other problems besides a non-stop fan in sleep mode? Does your PC become inoperable once it enters sleep mode?

If yes, you might have a corrupted file or even malware that’s causing all your headache.

Now, to scan and remove malware from your Windows system, you’ll need to install a good antivirus.

Initially, I recommend performing boot time scans where possible to get rid of stubborn infections that make use of active processes or files that run at startup to keep themselves intact even after attempts are made for removal.

Moving on, scanning and fixing corrupted files won’t require any additional software. To do this, you can just follow the given steps:

1. Take a backup of your Windows PC.
2. Go to Search and type in cmd to bring up the Command Prompt and then select Run as administrator.
3. Type in the command — chkdsk /f /r /x and press Enter. Press Y on any subsequent prompt.
4. Reboot your System. Windows will begin checking the local drives and fixing any potential problems. This can take up to several minutes, and you’ll need to be patient along the process.
5. After the System boots up, again open the Command Prompt, type in the command – sfc /scannow, and press Enter.
6. Wait for a few minutes as Windows scans all the system files. It’ll replace any corrupt file it finds.

6. Troubleshoot by Removing Recently Installed Software

Sometimes, certain apps or software you’ve installed on your System can prevent the PC from entering sleep mode or even automatically waking up from sleep mode. 

As such, this can cause your fans to start spinning even though you know you recently put your PC to Sleep.

You see, with the introduction of the Modern Standby with Windows 10, Microsoft also included components called Activators which can directly communicate with the power manager and prevent sleep mode from starting, thereby causing the fans to keep spinning.

Here’s a Microsoft Technet post going over a user whose PC fans wouldn’t turn off in sleep mode because of their newly installed printer.

They configured it as a network printer, which was causing the problem. After changing it to “local printer,” the fans behaved normally.

As a network printer, it was recognized as an Activator by the OS and thus kept the PC from properly falling asleep and keeping the fans running.

With this in mind, if you recently installed an app or software with this Activator component, it can potentially cause the problem you’re facing. 

Now, the quickest way to troubleshoot this issue is by uninstalling the software and checking if the fans keep running in sleep mode. 

Alternatively, you can also use the SleepStudy tool to check what activities prevent sleep mode from kicking in.

7. Check the Windows Event Viewer for errors

Do you get any error messages when you open your Windows PC from Sleep mode? If yes, it might help to diagnose what’s wrong with your system and why the fans won’t stop running.

I’d suggest that you head over to the Windows Event Viewer to see any error codes it might have captured.

To access the Event Viewer, go to Search and type in “Event Viewer,” and open the first app that pops up.

Inside the Event Viewer, from the left side panel, navigate to Windows Logs > System. Here, you’ll find all the error codes related to any recent system malfunctions.

Look for error messages that coincide with the time your system went into sleep mode. If you find one, take note of the Event ID. 

The Event IDs won’t make too much sense to regular users, but it holds a lot of information about what’s wrong with the System.

Now, without knowing the exact error message and the Event ID, I can’t provide you with a potential fix.

As such, I suggest that you paste the Event ID on Google and see if any potential solutions are available. 

If not, you can go to Microsoft Support Forums and mention the Event ID along with the problems you’re facing (PC fans keep running in sleep mode) and the steps you tried to fix them. An authorized technician should be available to help you out.

Key takeaways

If your Windows PC fans are running even when the System is in sleep mode, you can automatically run the Troubleshooter to diagnose and fix potential problems.

If that doesn’t solve the problem, you can check if Modern Standby is enabled. If yes, disable it. Also, head over to the System BIOS and enable smart or auto fan settings.

Other than this, you can check to see if sleep mode is properly configured, scan for malware or corrupt system files, troubleshoot recently installed apps, and even check the Windows Event Viewer for system errors.