yeah most likely was CPU overheat.
try to see if there is a thermal power control in the BIOS setup? set that up. It controls the fan speed, etc
And its best to invest a little into a better CPU fan, which cools better and makes almost no noise.
Maybe one from Zalman or Thermaltake
I have used both, both are
like this one:
::: Zalman, leading the world of Quiet Computing Solutions :::
or this:
Thermaltakeusa»Cooler»CPU Cooler»Intel Socket LGA 775»V1 : V1 CL-P0401
I'd recommend Zalman above Thermaltake.