NIS 2012 had been running fine until I did a secure erase of my HDD and then restored my OS, programs, data, etc. from my backup image. Out of the blue an NIS dialog box popped up saying "Critical Error". I didn't write the error down. I think it was either 3015,1 or 3051,1. At first I ignored the message because I thought NIS was complaining about something being wrong with my PC and I knew there was nothing the matter with it. But then Windows 7 alerted me that NIS had stopped functioning and that I was without virus protection. Sure enough, when I tried to run NIS nothing happened. No error message, nothing. So I ran the Norton Removal Tool and rebooted the PC. Then I reinstalled NIS. The installation appeared to run but when I clicked on the "Explore" button at the end, nothing happened. No error message, just nothing. Clicking on the NIS program icon also resulted in no response whatsoever. At this juncture I have removed NIS from the PC and I am using a different anti-virus program. If anyone has any ideas, great. Otherwise just consider this as an FYI in case anyone else reports similar behavior in the future.