Avast Free Antivirus review

Avast Free Antivirus is the most complete free package for a Windows 7 PC. Avast's requirements list Windows 11, 10, 8.1, 8 and 7 in both 32-bit and 64-bit editions, excluding Starter and RT. File Shield checks every file that is opened or added, Web Guard blocks scam sites, phishing links in email and malicious downloads, and Ransomware Shield stops untrusted programs from encrypting protected folders. Network Inspector checks your Wi-Fi network, and Rescue Disk can boot a PC from a USB drive to clean it. The catch is age-specific. Avast says Windows 7 needs the Convenience Rollup Update for current versions; without it, the PC stays on version 21.2. On Windows XP and Vista, the final version is 18.8, which still gets virus definition updates but no application updates or support, and Avast says those definitions are no longer tested on XP. The listed 4 GB of RAM is also more than many older PCs have.

Who it is for

Windows 7 SP1 users who want a full-featured free antivirus, and XP or Vista users who already run Avast 18.8.

Price

Free.

Download a free antivirus for your Windows PC or laptop to help detect and isolate potential cyberthreats.
Quoted from the vendor pricing page on November 10, 2026.

Key features

• File Shield scans any file added to or opened on the PC
• Web Guard blocks scam websites, phishing links in emails and malicious downloads
• Wi-Fi network security and Network Inspector for home and public networks
• Ransomware Shield stops untrusted apps from changing, deleting or encrypting protected files
• Rescue Disk to boot and scan a PC from a CD or USB drive

Strengths and weaknesses

• Strength: Requirements list Windows 7 in 32-bit and 64-bit editions
• Strength: Avast 18.8 on XP and Vista still receives virus definition updates
• Strength: Free version includes ransomware protection and a rescue disk
• Weakness: Lists 4 GB of RAM and 2 GB of disk space, heavy for many old PCs
• Weakness: Windows 7 needs the Convenience Rollup Update for current versions
• Weakness: XP and Vista users get no application updates or technical support

Key facts

• Windows 7 requirement: SP1 with the Convenience Rollup Update for current versions
• Last XP and Vista version: Avast 18.8, definitions only
• Hardware: 4 GB RAM, 2 GB disk
• Excluded editions: Windows Starter and RT

Where it ranks

Avast Free Antivirus is No. 1 in our Best Antivirus for Older Windows PCs verdict.