New cpu cooling fan

I have a pc a friend built for me a long time ago, but it’s starting to have temperature issues. The cpu regularly gets cranked to 100°C whenever I use it for anything, and im not sure what to do. I was thinking of replacing the liquid cooling system for the cpu since it doesn’t appear to be cutting it. It’s some kind of nzxt fan, kinda looks like a kraken but im not sure. Does anyone have any recommendations for a cpu cooler that would work for an intel core i5 7600k?