problem solved. thanks so much. i wasnt optimistic, but i followed your suggestions logically and methodically, using the 4 cards and 2 slots that i had. i fact it was just a contact problem, but i wouldntve known that: the cards and slots now work ok. my-computer-properties now reports 992MB instead of 480MB ram, and the machine is noticeable faster. good enough for me. thanks again. tim!