Don’t waste your system resources and money by purchasing and installing a local antivirus. It’s a known fact that the realtime protection of a local antivirus it’s a considerable overhead even for modern processors. Due to this fact powerusers prefer to use their antivirus only for occasional scans of downloaded files.
If you are one of those users who can live without a realtime protection then you should consider an online antivirus. By installing latest security packs and using common sense and extra care when navigating on the web almost everybody will find an online antivirus sufficient.
A very good online antivirus is BitDefender Online Scanner