If you're not satisfied with NIS, many of the members use the below A/V's. Whether you have the trial or full version installed, downloading and running the Norton Removal Tool, is recommended prior to installing a different A/V.
Avira AntiVir Personal - FREE
Avast Free Antivirus
If you're looking to replace Norton with another suite, I'm sure you'll get varying opinions from other members.
Best of luck..
I recently got a new Compaq Presario CQ61 with Windows 7. It came installed with Norton Internet Security. The technician at the store told me the system came with fully installed software, but Norton keeps asking me to pay for a full version. The thing is I don't mind paying for a full version but I'm afraid Norton is weak and not a very good strong anti-virus. What do you suggest?