i think if it says "prescott d" it's just a single core prescott. but i think like the amd dual cores the intel also just use two of their current cores on one chip, so it could be just named incorrectly wherever the info is from. i was under the impression that the pentium d was a "smithfield core". not sure though because i don't follow intel much. also if this is a prebuilt computer you've bought they would probably have made **** sure you knew it was dual core in their sales pitch.