Mack-a-fee with the emphasis on the first syllable.

The news guys have said Ma-caf-ee, Ma-caf-ery, Mac-affree, you name it...everything except the right way. And McAfee has a major develoment center in this area (the high level guys who develop the code to defeat these viruses) so it would take only a simple, local, phone call to learn the right way to say it. If I were a news reporter and was so unsure that I said it differently each and every time I said it, I'd have made that call before air-time!