From a previous study we have determined that commercial security products can suffer from a usability perspective, lacking the necessary attention to design in relation to their alert interfaces. The aim of the paper is to assess the usability of alerts in some of the leading Internet security packages, based upon a related set of usability criteria. The findings reveal that the interface design combined with the user’s relative lack of security knowledge are two major challenges that influence their decision making process. The analysis of the alert designs showed that four of the criteria are not addressed in any of the selected security measures and it would be desirable to consider the user’s previous decisions on similar alerts, and modify alerts according to the user’s previous behaviour.