Core i5 7600k 3.8 ghz won’t boot into windows at stock speed

[awesomelyawesome0327]

Okay so I started building this computer last November and recently got a core i5 7600k 3.8ghz
I used it with a gigabyte z170X gaming 7 mobo, the first week everything worked fine it would turbo to 4.2ghz just fine and everything but after a while I want to try to overclock it, I saw a cpu upgrade option in the bios with different OC defaults so I tried 4.4ghs and it worked good but I wanted more and the last option was 4.6ghz and that worked for about a week intil it wouldn’t boot into windows anymore so I had to start going lower and lower cause all I would get is blue screened and now I’m down to only being able to boot at 3.5ghz below the stock clock speed and I can’t even get windows to boot at stock speed without getting blue screened
I figured the motherboards chipset or something was fried I honestly didn’t know so I got a new motherboard (ASRock Z270 gaming k6 pro 1 series) and the same problem is happening I really need help idk how to fix whatever is going on
Pc specs are as followed:

Rosewell 650w
Msi gtx 1060 6gb
Core i5 7600k
And both motherboards that I mentioned above

Please help

 

[MrChicken]

Do you have any ideas of your cpu temps during overclocking? Did you apply thermal paste on the cpu?

 

[awesomelyawesome0327]

Do you have any ideas of your cpu temps during overclocking? Did you apply thermal paste on the cpu?

 

[awesomelyawesome0327]

Yes I obviously put thermal paste on my cpu my temps were 100 degrees Fahrenheit the highest the temps ever got was maybe 115 Fahrenheit

 

[Rexer]

I imagine you have the latest bios so let me ask, did you teak up the voltage while reaching those speeds?