If you used Software Update to make the upgrade to 10.3.6, i recommend that you go to the Apple Support/Download site and get the standalone 10.3.6 Combined Updater. Use Internet Explorer to access the website if you can't get Safari to run. This approach has proven successful for others who had problems with the Software Update version. D-B >>> After upgrading to 10.3.6, Mail, Safari, SW Updater, Disk Utility, >>> etc... (all Apple programs) either would not run at all - or would >>> start to run, then do the spinning beachball of death routine... >>> >>> All non-Apple software performed normally.