Situation:
You installed Norton Internet Security, Norton AntiSpam, or Norton Personal Firewall, and you completed the product activation successfully. However, whenever you restart the computer you are prompted to activate the program again. If you enter the activation code each time, then after a number of restarts you see the message "The trial period has expired. This product has been disabled because you have not activated it."

Solution:
This issue is caused by a problem with the Symantec Product Activation feature. Product Activation is an antipiracy technology designed to verify that Symantec software products have been legitimately licensed. For a description of the Symantec product activation feature, read the document What is Product Activation?

This problem can be fixed by following the steps outlined in the document Your Symantec product prompts you to activate whenever the computer restarts.