I have signed up for a service bundle with Comcast which includes Norton Security Suite. Will Avast!Free be compatible with that Norton Suite or will I have to remove Avast!Free? (Avast!Free is currently working with Windows Defender, and with Super AntiSpyware). I have Windows XP Home. I currently have dial-up but with Comcast I will have high speed.
Never will anything Norton be compatable with avast!
When you have Comcast High Speed you will have to choose with avast! or Norton 
Just call Comcast and tell them you do not want Norton, which is probably not as effective anyway coming from your ISP…problem solved. The AV’s that ISP’s offer are optional services.