Doing the right thing?

Dear Help group,

My Computer is Windows 98 SE, AMD, Athlon XP 1800+, 384 MB RAM

I protect it with Norton Anti-Virus 2001 (always updated with new def.),
Zone Alarm firewall, Spybot S&D, Adaware.

My question is about the Norton Anti Virus. When I purchased the first
annual def. update it was about $ 9.00. the next year it was about $ 19.00.

Am I doing the correct things to protect my PC? Should I continue to
purchase the Norton AV updates or switch to another software protection?

Your help will be appreciated.

Thanks.

Jeff Turner Gates Mills, Ohio