Download Avast Free Antivirus on your Windows, Android, and Mac. World- leading antivirus, compatible with all Windows operating systems. Free forever. Protect your devices with the best free antivirus on the market. Download Avast antivirus and anti-spyware protection for your PC, Mac and Android. Best free antivirus for Windows 7 from market leaders - protecting 400 million people. 100% protection against viruses, spyware, ransomware and all malware. Free essential antivirus and anti-malware protection with added privacy and performance-boosting features. Call blocking, app locking included.