After installing Internet Security 2009, it seemed to work, but I soon noticed several Windows XP services stopped working, including the Search Companion and the Help Center. After uninstalling Internet Security and rebooting I found those services still wouldn't work. I can't use the System Restore from Help Center which won't start, and starting System Restore from Safe Mode or using msconfig just leads to a blank white window. Reinstalling Search Companion and Help Center does no good. It appears Internet Security 2009 did permanent damage to my registry. Also, I cannot now reinstall the Norton SystemWorks that was apparently disabled when Internet Security was installed. All I get is a window asking for activation but with a window title of "%s" and no response to pushing the "Acivate now" button.
The last time I tried to use a Norton product I accidently installed the Norton GoBack. That repartitioned my hard drive and damaged my computer to such an extent that I had to buy a new computer. I can't believe I fell for this again.