Old CPU running hot

[PumkinFest]

i am cleaning up an old system (P3 1GHZ) and the heatsink was covered in dust, so i take it off and clean it, put it back on and now the bios is telling me the temps are around 55 degrees where as before they were around 42???

 

[PurdueRy]

did you put on new thermal grease? try reseating the CPU

 

[kamranziadar]

make sure you put the heat sink correctly