yesterday i upgraded my intel pentium 2.60GHz to a Intel pentium D 3.4GHz. i removed the heat-sink cleaned it off replaced the thermal paste but the cpu kept overheating i notticed the heat-sink fan stayed at 550 rpm and it wont go faster i check the BIOS and it has smart fan running but it wont speed up when its needed. Please help
How much thermal compound did you use? You have to use very very little. Also once, you place the heat sink, don't lift it up again.
As far as the bios goes, try setting the fan on manual at the highest speed. Then test the machine. If it still overheats, then the problem is most probably bad placement of thermal compound or bad seating the heat sink.