Microsoft delivered the final, public version of its Microsoft Security Essentials (MSE) utility, a free antivirus and anti-malware product for Windows XP, Vista, and 7. This is available as free download for any Windows XP SP2 or later OS for every genuine copy of the operating system.
Click hear for more information and download. I would highly recommend that you have it installed as its fast, snappy…. moreover it uses the same engine which is used by our Forefront security products.