My PC fan starts rotating very fast when i boot to windows

[carlos prosodio]

So i woke up and turn on my PC and there whas no hp logo and it starts beeping , so i turned it of and open it to ser if anyting whas wrong but there whas nothing, so i tried to turn it on again the HP logo doesnt appear i press f1 to boot and at the windows 10 logo the fans start rotating very fast and then it starts to slow down and it starts againd doping this on a loop until it starts rotating even faster and faster.
My PC is a HP compaq pro 6000
It has a core 2 duo 2.93gh e7400

 

[carlos prosodio]

I cleaned the CPU and the RAM and put new termal paste and nos its working.