Tencent PC Manager
Tencent PC Manager is a powerful antivirus engine from Tencent. It includes the largest security cloud base all of the world. It is a freeware program which does not have restrictions and it's free so it doesn't cost anything.
Tencent PC Manager has many other features, including vulnerability remediation, system cleanup, computer speed acceleration and software management.
Tencent PC Manager will constantly monitor your system and automatically scans any files downloaded from the Internet to prevent infection virus.
Tencent PC Manager has a simple, stripped-back interface which covers the bare antivirus essentials only: basic status details ('files scanned today'), a button with three scan types (Quick, Full, Custom), links to three maintenance panels (Quarantine, Whitelist, Scan Logs), and a Settings box with some options and tweaks. If you've any experience with antivirus packages, you'll be feeling at home with Tencent PC Manager within a couple of minutes.