Heard that U.S. Active Duty Servicemembers can download a McAfee AntiVirus program for free. Anyone know how?

One of those "friend of a friend said.." situations, sounds too good to be true but then again I'm kind of illiterate when it comes to defending my computer against harmful things... I thought that AVG AntiSpam-thingy would do the job just fine. Guess not. Any help much appreciated.