Yesterday, Precision 7550 abruptly shut down. On restart, BIOS indicated overheat. On restart, ran Dell diagnostics, everything OK, including fan, which switched ON and OFF. Downloaded Dell Power Management, found was set to "Optimized". Set to "Cool", heard fan briefly run, then OFF. Downloaded Core Temp application. When idle, cores show mid 40s celsius, but with activity cores rise to low 80s and one hit 100C. Would like to lower temperature threshold when fan is run but Dell does not appear to allow user such control. Found third party utility to lower temperature threshold but could not install [2007 post]. What can be done to lower temperature threshold when fan is run?