Accuracy on the thermal probes' signals is far from great on a large percentrage of MB's. You didn't mention either the MB model or the HSF that are in your friend's problem PC. One of my PC's has an XP 3000 in it that MBM5 reports as idling at 51 Celcius. I can take the side off that box, and reach in to wrap my hand and fingers around the Vantec AeroFlow TMD heat sink device without feeling any warmth from the base until the reported temp is 60-61, at which point it's still not even luke warm.
This is on an A7N8X-X, in a Kingwin 424 box that is well ventilated. The AeroFlow TMD got decent "benches" from the web site that keeps the HSF database, while being quiet. Various comments over the past couple of years seem to reflect a tendency of some temp sensors to report exaggerated numbers.
Before getting terribly excited about the current idle readings, have the friend use more than one reporting tool for some comparisons of readings, and perhaps hold his hand/ fingers near the base of his HSF, not necessarily touching it if it really is too hot . .
