Avast Antivirus Installer High Disk Usage? Full Guide

If you use Avast Antivirus software, you may have experienced the Avast Antivirus Installer High Disk Usage of your computer. Well, this is a common problem of Avast.

Sometimes you might have faced the Avast Antivirus Installer high disk usage problem. It is all about facing slowness in your computer while installing Avast on the device.

If you read about Avast software, you will find that it generally uses high disk space to operate properly. But it sometimes becomes problematic as the computer becomes slow for this.

But do not worry, because there is a solution! I am going to talk about how to solve Avast’s high disk usage problem in this article.

Avast Antivirus Installer High Disk Usage – Easy Fix

Before proceeding, you need to know if Avast is using all the disk space or not. You can figure it out by following a few simple and easy steps.

  • Right-click on the taskbar and click on Task Manager to open it.
  • Search how much CPU is Avast utilizing by searching for it under the Background Processes.
Avast Antivirus Using All The Disk Space? Know How To Solve This!

If you find that Avast is using a large amount of your available disk space, then you have to follow the steps to reduce Avast’s disk usage percentage.

There is more than one method to reduce the disk usage percentage of Avast. I shall state all the methods for you.

Avast Service High Disk – How to Solve

As I said, there are several ways to fix the Avast service high disk usage problem. I am stating the methods below one by one. Choose whatever you find easier.

Method 1 – By Removing Avast Cleanup

When you install Avast, it installs with several other components as a part of a package. One of the components is Avast Cleanup.

If you are having trouble with Avast’s high disk usage, you can try to fix it by removing the Avast Cleanup service. This will fix the Avast antivirus engine server’s high CPU usage.

  • Double-click on the Avast icon to open the Avast tool.
  • Open Settings.
  • Click on Components at the left pane of the Avast window.
  • Choose Cleanup, click on the down-arrow symbol, and choose Uninstall Component.
  • Click OK when the prompt appears to complete the action.
  • Restart your computer.
  • Check the performance using Task Manager.

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Method 2 – By Stopping Avast Screensaver Scanning

  • Open File Explorer.
  • Open any available file and right-click > Scan with Avast. By this, the Avast console will show the list of files that are presently being scanned. By taking a look at the files, you will know why the CPU usage is so high.
  • Open Avast Screensaver scan.
  • Click the Stop button to stop the procedure.
  • Go back and check the current CPU usage in the Task Manager.
Method 3 – Repair The Tool

If you don’t like the above-mentioned two methods, or these procedures don’t work for you, you can try the third method to fix the Avast using the 100 disk problem.

  • Type Control Panel in the search bar of your computer and open Control Panel.
  • Right-click on Avast and select the Uninstall/Repair option.
  • The uninstallation wizard will show the options – 1. Update 2. Repair 3. Modify and finally 4. UNINSTALL. Click on Repair.
  • Click Confirm.
  • Click Finish.
  • Restart Avast.
  • Restart your computer.
  • Check the CPU usage in the Task Manager.
Method 4 – By Updating Avast

Sometimes an older version of Avast might cause a high disk usage problem. You need to update Avast if you find Avast using too much CPU.

  • Open the Avast tool.
  • Open Settings.
  • Click General in the left pane. This will show you the Update option for Avast.
  • Click CHECK FOR UPDATES in both sections. The first one is for the database update, and the second one is for the application update.
  • Restart your computer once the process finishes.
  • Check CPU usage in Task Manager.

N.B. – DO NOT uninstall Avast as it is a very important and necessary tool for the safety of your computer. It protects your computer from possible threats like malware, spyware, or virus.

It gives you both offline and online protection too. So it is not recommended to uninstall the Avast antivirus program. But if you want to uninstall it, make sure you install any other good antivirus software to ensure your system’s safety.

Avast High Disk Usage At Startup – Easy Fix

If you find your computer is taking so long during startup because of Avast, you can try a Clean Install of Avast.

Avast Antivirus Using All The Disk Space? Know How To Solve This!

How To Perform An Avast Clean Install
  • Download the correct version of Avast.
  • Uninstall the Avast software presently installed on your computer.
  • Disconnect the internet and reboot the computer.
  • Connect to the internet again.
  • Install the latest downloaded Avast.
  • Reboot the computer again.
  • This is how you Clean and Install Avast on your PC.
Avast High CPU Usage When Downloading

This is a common problem Avast users face when they are downloading any file from the internet. To get rid of this problem, you can try turning off the File Shield.

File Shield is found to be the main cause of Avast’s high CPU usage while downloading, thus turning this off might solve your problem in this case.

  • Open Avast.
  • Find Protection > Core Shields.
  • Disable File Shield and reboot your PC.
Sysmain High Disk Usage

Sysmain, previously known as Superfetch, might cause the problem Avast service high disk usage in Windows 10 computers. Sysmain is a Windows 10 feature. If you want to stop this problem, you have to stop Sysmain.

  • Type Services in the search box and click on it to open.
  • Find Sysmain and double-click it.
  • Set the Startup type as Disable.
  • Click Stop.
  • Click OK.
  • This will fix the problem of 100 percent disk usage in Windows 10.

Frequently Asked Questions

  • How Do I Fix A High Avast Disk Usage?

You should try to fix Avast’s high disk usage problem by uninstalling the other Avast components like Avast Cleanup, updating Avast, repairing the installed Avast software, stopping Avast screensaver scanning, or performing an Avast clean install.

  • Why Is The Avast Antivirus Installer Always Running?

It is probably because you need to update the Avast driver. Try to reboot your computer and check if it is replaced by a button called Avast Driver Update. If you get this button, update the driver and your problem will be gone.

  • How Do I Stop Avast From Using My CPU?

You can try several fixes like removing Avast Cleanup, updating Avast, disabling File Shield, and removing unnecessary Avast add-ons.

  • How Do I Fix System High Disk Usage?

Remove Sysmain from your computer. Type Services in the search box and open it, go to Sysmain, set the Startup type as Disabled, click Stop, then OK.


This is all about how you fix Avast’s high disk usage problem. Hope this article will help you and you will be able to get rid of this annoying problem. Best of luck!

Read More: Service Host SysMain Causing High Disk Usage? – Best Solution

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