Microsoft Security Essentials

The only free security product we've tested this year, Microsoft's Security Essentials, is our default recommendation of what to install to provide your PC with a bare minimum of protection against malware. It's only available for Windows 7 and below. Windows 8 has its own integrated Windows Defender, which looks just like Microsoft Security Essentials in terms of its interface, but which appears, in preliminary tests, to behave differently when confronted with malicious software. Security Essentials protected our PC in 85 per cent of malware exposures. Admittedly, it only completely blocked 57 of 100 viruses, but it neutralised another 28 after the process of infection had begun. In 15 cases, it failed to protect us. That's better than having no protection at all, but 15 infections is not good. It did well in our false positive tests, only blocking one legitimate program, giving it a total accuracy rating of just 233.5. Once you've installed it, Security Essentials prompts you to begin an initial scan. With that done, it'll schedule a weekly quick scan and use real-time protection to monitor potential threats as you encounter them. The main screen informs you of whether or not your PC is protected and Security Essentials is active and up-to-day, as well as giving you instant access to quick, full and custom scans. The Update tab is exactly what its name implies: you get an update button and information on the last update times of your virus definitions. The History tab is a bit more interesting, displaying a list of all the quarantined items that have been prevented from running on your PC. You can permanently remove them or - if you're sure a program really is benign - restore it, although it's worth bearing in mind that Security Essentials has a very low false positive rate. You can also view lists of items that you've allowed to run and which have been detected as potential issues, but neither quarantined nor allowed. The final tab gives you fine control of Security Essentials' settings. As well as scheduling scans and enabling real-time protection, you can customise the way the program deals with the threats it detects, depending on how severe it believes them to be and exclude specific files, processes or locations from your scans. You can also enable the scanning of removable drivers and change the amount of information Security Essentials sends back to Microsoft about potentially unwanted software. Microsoft Security Essentials is brilliantly simple and easy to use. For obvious reasons, it integrates perfectly with Windows. However its relatively low rate of malware detection makes it a distinct second-best to the commercial anti-virus suites we've looked at this year. It'll do as a stopgap, but we strongly recommend buying Kaspersky Internet Security 2013.