I agree with a couple of you. Do you have a clean pc you can use? If you do, take your Norton, install it. Update it. Then creat some rescue disks. Be sure and write protect them after you create them. Return to PC in question, use rescue disk on it. If there is anything on the pc that is defined on the resuce disk's it will find it, and either clean in or quarantine it. If it quarantines it, just reboot. Then go into Norton, and either clean it or delete it.

Without a little bit more info that is the best advice I can give you. You also might try downloading either spybot search and destroy, and or adware. Boot to safe mode and let those guys do their job. Also, after you use one or both. You should clean up your registry with Regcleaner. Just let it clean up all dead registry links.

If you are still having problems after any advice herein or above. Come back, please give detailed information.

Good luck
Be safe and stay free