i7-4790 overheat

Hello, So I bought a used processor, thereby doesn't seem to be any defects that I have noticed. I made sure my bios was updated, thermal paste was put on properly all seemed to be good and dandy. But when I reset my bios to default setting of the chip it just won't go into windows. At times...

Hi i have a dell optiplex 9020 small form factor (i7-4790,16GB(2x8GB ddr3 1600),MB: 0xcr8d with intel Q87 chipset) and use for rendering and gaming. average of temp of i7-4790 with defult dell cpu cooler and heatsink is about 75C and peak of cpu temp is 90C and overheat. please recomended me...