MS anti-virus is official

[dparm]

$50/year (http://www.theregister.co.uk/2006/02/08/windows_antivirus_protection/)

I guess we'll have to wait for it to be tested to see just how effective it is at in-the-wild detection (which is the true indicator of anti-virus performance).

[sfontes]

I dunno. An AVSoftware by the same company whose OS has new viri written like..every day b/c the OS has so many holes? It will be interesting to watch it...

[dparm]

Excellent reading (http://answers.google.com/answers/threadview?id=569374)

How do other anti-virus programs compare to each other? Read the above link. Note this is for commercially-available software (precisely why Sophos is not listed).