Following a year-long development phase and several months in limited public beta, Microsoft has finally released the full version of its anti-malware scanner today -- Microsoft Security Essentials. Formerly codenamed Morro, this free-of-charge replacement for OneCare is designed to provide consumers with real-time protection against Trojans, computer viruses, spyware and rootkits.

Although it lacks the personal firewall, backup and PC tuning features found in its late sibling, Security Essentials has fared quite well against similar suites in tests conducted by PC World, and at the very least it will help Microsoft get a larger percentage of the Windows ecosystem protected by security software.

Its interface has been made very simple for users of all backgrounds, with only four main tabs to choose from, whereas more experienced users will still be able to customize their choice of protection. Looking to placate concerns about resource hogging and nagging, Microsoft promises Security Essentials is designed to run quietly in the background, alerting the user only when there is an action for them to take.

Also, in addition to taking advantage of daily signature downloads, the software is reportedly able to validate suspicious files against newly identified malware in near-real time by querying the 'Dynamic Signature Service'. Overall, it looks like Security Essentials has a lot going for it and could turn out to be a real contender in the free antivirus arena. If you are interested in giving it a try, XP, Vista and Windows 7 versions of the software can be downloaded here -- the only restriction on use is that it has to be installed on a "genuine" Windows PC.