I am running XP SP3. I installed NIS 2011 software, and it installed correctly. My computer shuts down correctly. But, every time I shut down or reboot my computer, scan disk runs to check for problems when the computer starts. Most of the time nothing is found, sometimes it will find lost chain files and correct them. This scan disk operation just started after I installed NIS 2011. I did have NIS 2009 installed, and have run the Norton removal tool several times. I used another Anti Virus, then removed it and returned to NIS. Any ideas ?