ClamWin Antivirus is an effective, free, open code antivirus, whose database automatically updates via the Internet.
As an advantage ClamWin Antivirus can be integrated into the Windows Explorer contextual menu, to analyze files, and also in Microsoft Outlook. This way, you are protected from the easiest way into your PC: via email.
In addition to all this, ClamWin Antivirus offers all the basic options and functions of a good antivirus: you can program a system analysis every so often, there is space in quarantine for damaged files, it offers complere reports, etc.