Shoutbox

Considering Microsoft are new to this field, it's a decent program. However, as many people will tell you, it does not detect viruses too well. However I can see this taking off in the future, and outdoing AGV and other free anti-virus programs, it's Microsoft after all, they usually do try and make their software as good as they can. The exception being IE, up to now, however they are even trying with that now.

I can't see them outdoing McAfee or Norton, they've owned this market area for so long, and they are the most experienced also.

At the present time, it's not for your average home user as it isn't that reliable; of course it's better than nothing. However there are better free alternatives out there.