I uninstalled an old version of NAV and installed a new version on two HP DM4 laptops running Win7 Home Premium SP1. On one laptop the program runs as designed. On the other I get the message, "Norton antivirus has stopped working" when I click "Scan now", "LiveUpdate" or "Advanced". I have uninstalled and reinstalled several times including once using the Norton Uninstall and Reinstall Tool. I made no system changes between the old and the new.programs. Any idea on what I need to do here? Thanks.