Avast Antivirus for Windows is security software that prevents viruses, spyware, and malicious threats from infecting your PC. Here the topic includes instructions to download and install Avast Free Antivirus software Make sure no other application or antivirus software is running on your PC.Visit Avast Antivirus’s official site and click on the download link to download the Avast Free Antivirus setup file, and save it on the local drive destination on your PC, by defaultdownloaded files are saved to your user’s Downloads folder.Right-click the downloaded setup file avast free antivirus setup online.exe and select Run as administrator from the context menu.NOTE - If do not appear the Run as administrator option, then it refers to instructions to manage administrative accounts on your PC:Managing administrative accounts on your Windows PC