I have Norton 360 installed on a presario s4200nx & it is slowing the pc
down alot.
Which antivirus & firewall would you recommend using? I have been thinking
about trying Avg free & Zone Alarm.
And,what's the best way to remove all of the Norton?

You could always try the program formerly known as Dell Decrapifier
(now at www.pcdecrapifier.com)

As an alternative to AVG free, how about Kaspsersky for free ?

http://www.activevirusshield.com

It was made available via a deal with AOL, but you don't need to be
with AOL to use it. Don't bother installing the toolbar (some utils
wrongly report it as spyware anyway).