Latest research from the Yankee Group shows that nearly half of all businesses have virtualized some portion of their data centers. This means that there is a very good chance you are in the midst of a virtualization initiative, or soon will be, in order to cut the costs of operating your data center, DMZ, mission critical applications, or desktop environment. Standing in the way of realizing virtualization’s promise, however, is security. And going forward with your virtualization initiative without addressing visibility, protection, and compliance can prove problematic, as malware targeting virtual networks proliferates, and standards mandating granular virtualization security become ratified. This paper lays out five "best practice" ways to fortify your planned or existing virtualized environment, ensuring that it is architected for security, malware suppression, and regulation compliance.