There are three Antiviruses in the free antivirus market that are competing with eachother. These include AVG Free, Avast! Home Edition and Avira Antivir Personal. Avast! pulls in on a close lead with AVG Free in second place. Avast shows its colors with its real time scan engine, which they include with the free edition, unlike AVG Free. However, as far as real time scanning is concerned, it can and does use up more resources than AVG and Avira – so it's probably not best to install all the features of Avast! antivirus onto a computer that is already having speed issues.

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