Oh, how I hate the Dell inspiron 1420 retail line. lol. Try running memtest on your system. My theory is your
RAM might have corrupted cells or addresses. I have seen a lot of
RAM issues with the 1420, due to cheap types of
RAM being puit in the system.
Another thing you can try, is a complete uninstallation. MEaning uninstall the appliaction using add/remove programs , then the office folder nder local settings udner your username. Also remove the reminents left over in program files. Then go to start-run-regedit and remove all office classes. Reinstall

