Boker tov,
Norton is a strong suite.
System image backups, as mentioned by others, is a great way to recover from almost any mishap.
Depending on how you got infected last time, you might want to do one or more of the following:
1 learn and practice safe user habits (think before you click, maintain a healthy suspicion of anything unknown, even if it claims to come from someone you know and trust, etc)
2 add another security app, such as voodooshield, for instance
3 make greater use of native Windows protection mechanisms (user access control set at high, standard user account, etc)
Number 1 is the most important, for everybody.