Comcast is the only provider that provides Norton to its users free. Norton used to have a number of issues pre-2009, but after they scrapped their software and started from scratch it's become our preferred anti-virus software. You can get this from Comcast's website, but it usually includes a bunch of extra software (such as Constant Guard) that we are not a fan of.

However we've got a link that will take you to Comcast's Norton download without Constant Guard or any junkware.

https://idp.comcast.net/idp/startSSO.ping?PartnerSpId=www.symantec.com  [1]

We recommend anyone on Comcast download this great benefit.