The microprocessor is the key component in all type of PC systems. As the performance of all computer operations totally depends on microprocessor and health of this microprocessor affected by heat energy or temperature. If the temperature of this microprocessor is kept within permissible limit then the life of microprocessor increase and this is done by a component called heat sink. There are few design parameters which affects the heat transfer rate of heat sink like fin shape, material, the thickness of fin, number of fins, the spacing between two fins and base plate thickness etc. instead of aluminum copper has high heat transfer rate but as cost increases it cannot use copper as sink material. As base plate thickness increases the rate of heat transfer also improve but because of space limitation of every heat sink in the computer we cannot increase this base thickness beyond the limit. Also, increase the number of fins is not feasible solution to increase the performance of heat sink. So finally the shape is the parameter which is studying in this work for optimum results. Here in this work different shape of fin profile like circular, trapezoidal, rectangular and triangular are consisted of numerical study using the ANSYS software. According to the results, it is clear that heat transfer rate is increased by using triangular fin shape as compared to rectangular fin heat sink. The modified triangular heat sink shows that there was an increase in heat transfer rate by 9% as compared to rectangular fin heatsink.