Open File - Security Warning

I have a question. I had a virus on my computer which was the Trojan.cachecachekit or W32.Spybot.NLX. I have successfully deleted the file by scanning my system with Norton Internet Security, but when I restarted my computer I still got a box that stated, "The publisher could not be verified. Are you sure you want to run this software?" When I pressed run, it didn't do anything, is there a way I can this message off my computer, so it doesn't keep coming up everytime I turn my computer on. Hope you can help.