Didn't mention what Make & Model of CPU Cooler you have installed nor whether it is Air cooled or Liquid cooled.
Sounds like your CPU Cooler isn't correctly installed and not making good contact with the surface of the processor.
One way to find out is to remove the side panel from your computer case exposing the motherboard with the CPU Cooler. Turn power on and wait until it boots up.
Make sure the CPU Cooler fan is turning as soon as you power up.
Then once you are in Windows desktop, very carefully push down on the CPU Cooler and see if the Processor's temps immediately go down. If it does then that indicates you didn't install the CPU Cooler correctly.