The Student/teacher addition allows usage on 3 computers. The present one has the AMD 64 bit chip. The Outlook 2003 is SP3. The error message tells me to run Setup, select "add/remove features", change the feature to "run from my computer". Did this several times to no avail. What's next? How do you know that in fact you have selected the correct feature when there's no indication on the screen (during the Setup phase) that a feature is selected or de-selected?