How to Install Avast Antivirus: Step-by-Step Guide

Why Install Avast Antivirus?

Nowadays, antivirus software is a basic requirement for any device, whether you use a Mac or Windows PC. Whilst most modern devices come with some built-in virus protection, comprehensive security with endpoint response, malware blocking and protection against potentially unwanted programmes requires dedicated antivirus and security software.

Avast is one of the most reliable antivirus solutions available, performing above the industry average in independent tests. It offers an excellent user experience with a clean, simple interface — unlike some equally powerful antivirus products that can be confusing to navigate. Importantly, Avast rarely produces false positives, meaning it will not mistakenly flag legitimate software as harmful.

Download Avast Antivirus

Avast’s flagship products that you can buy in our Avast shop are:

• Avast Premium
• Avast Ultimate
• Avast Internet Security

But which one should you choose?

General Features

In addition to the general features shared across all editions, you should check the main differences between Avast Premium Security and Avast Ultimate before making your decision.

General Installation Procedure

• Click the download centre button in the email we sent you. If you are not yet a customer, click the link for the relevant product.

• The link will redirect you to the manufacturer’s website, where you will be asked to log in or create a new account.
• Follow the registration process and enter the product key you received from us when prompted. You will find this key in your email as shown below:

Install Avast on Windows

• Right-click the downloaded installation file and select “Run as administrator”.

• A User Account Control panel will appear asking for permission. Click “Yes”.

• If you wish to change the default language, click the language selector in the upper right corner and choose your preferred language. Then click “Install” to continue with the standard installation. If you want to customise the setup, click “Customise”.

• Wait for the antivirus programme to finish installing on your PC.

• When the installation is complete, click “Start”.

• Select “Activate” to activate your licence.

• Click “Run” on the first scan to start a full smart scan that detects viruses, malware, faulty browser extensions and other issues on your device.

• Restart your device and you are all set!

Minimum System Requirements (Windows)

• Windows 11 (except Mixed Reality and IoT editions), Windows 10 (except Mobile and IoT editions, 32-bit or 64-bit), Windows 8/8.1 (except RT and Starter editions, 32-bit or 64-bit), or Windows 7 SP1 with Convenience Rollup Update or later (any edition, 32-bit or 64-bit)
• Intel Pentium 4 / AMD Athlon 64 or higher processor (must support SSE3 instructions); ARM-based devices are not supported
• 1 GB RAM or more
• 2 GB free hard disk space
• Internet connection for downloading, activating and updating the application and antivirus database
• Recommended screen resolution of at least 1024 × 768 pixels

Install Avast on Mac

• Click the downloaded installation file to open a window.

• Double-click the “Avast Security” icon and close the window.

• Click “Allow”.

• After reading the Avast Privacy Policy, click “Next”.

• When you have read the End User Licence Agreement, click “Next” and then “Accept” to confirm that you agree to the terms.

• Click “Install” to continue with the standard installation. To change the installation location, click “Change installation location”. You can also customise the installation by clicking “Customise”.

• Enter the username and password you use to log in to your Mac, then click “Install Software”. You may be prompted for your password again and asked to click “Update Settings”.

• If you see the message “System extension blocked”, click “OK”.

• You have the option to uncheck the box if you do not want Google Chrome installed as your default browser. Then click “Next”.

• Click “Close” then “Move to Bin”.

• Follow the on-screen instructions to grant Avast Security the necessary permissions.

Minimum System Requirements (Mac)

• Apple macOS 12.x (Monterey), macOS 11.x (Big Sur), macOS 10.15.x (Catalina), macOS 10.14.x (Mojave), macOS 10.13.x (High Sierra), or macOS 10.12.x (Sierra)
• Intel-based Mac with 64-bit processor
• 512 MB RAM or more (1 GB or more recommended)
• 750 MB free hard disk space
• Internet connection for downloading, activating and updating the application and antivirus database
• Recommended screen resolution of at least 1024 × 768 pixels

Having Trouble with Installation?

If you purchased your licence from Licendi, you will find the licence key and invoice in your email. Looking for a different antivirus solution? See our guide on how to install AVG Antivirus or read about the 4 best Windows antivirus programmes.

We Have an Activation Guarantee

If your key does not work, contact us and we will replace it free of charge. Our licences must be activated within a certain period, after which they may expire. If you have followed all the instructions, downloaded and installed the file, but the licence does not activate the software, it is possible that the key has expired.

In that case, please fill out the form in our help centre and include a screenshot of the error message if possible. We will then send you a new key for immediate activation.

Remember that your licence entitles you to download and use all updates. Browse our full range of antivirus and security software to find the right protection for your devices.