100 is thermal throttle and you should bewell below those temps anyway. I would start by taking off the cooler, cleaning all the thermal paste of (alcohol and coffee filters work great), reapply new thermal paste (between a rice and pea size) and re-seat the cooler.
To be honest Intel coolers are junk, however those temps are still very high. If you do want to put an after market cooler on something like the Coolermaster 212, Cryorig H7 or even the Coolermaster T2 (which is under 20 USD) are all better choices.