World's largest home computer OS seller Microsoft Windows has been fixed for a fatal security flaw that was haunting it for the past 19 years. The bug has existed in every version of Windows since Windows 95, and would have allowed an attacker to run code remotely when the user visits a malicious website. IBM researcher Robert Freeman described the vulnerability as “rare, ‘unicorn-like’ bug found in code that IE relies on but doesn’t necessarily belong to.