First the specs:

Z370 Professional Gaming i7 

i7 8700K

32gb Gskill Ripjaws 3200

Cosair 750w Powersupply

Samsung Evo 128gb SSD

That is all I have running now as I have not been able to successfully clean install windows. I can post no problem, and am able to boot from a usb and run the windows installation without much issue. When I attempt to boot windows, I get to the spinning wheel with the ASROCK Logo. As soon as I see the windows logo, instant reboot, as if I hit the reset button on the board. I have tried mutltiple times to reinstall with the same error.

Ive tried two different samsung ssds, one confirmed working in my other system.

I RMA'd my ASROCK motherboard and got a new one ( two weeks later from newegg )... same issue

I tried switching out the ram, dropping down to one stick, same problem.

I tried using both a USB made with the media creation tool, and a DVD

I tried both gpt and mbr formatting on the drive.

Ive left the front panel of my case unplugged from the board ( what if it was a faulty reset switch ) nada.

I can pretty much sit in the bios forever, or in the windows install command prompt etc without any crashes.

I noticed in my Bios that the ram (3200) is set to 2133 and the cas timings were wrong. Fixed those and got farther, swore It was success and then it crashed a little bit into getting started, and on subsequent reboots, gets to the same place it always does.

Ive now ordered a power supply that is coming tommorow to switch that out although the one Im currently using worked in my old system with a 980ti running as well so my power draw should be lower now, even considering the 8700k.

Any ideas are welcome, Im going bald over here.

If so, try removing it and booting from the integrated intel graphics. See if that gets you further. Every little thing helps when troubleshooting.

Good luck.

Thank you, I forgot to mention that I am actually using the integrated graphics ( hdmi out ) on the board. I have not put the video card in the system at all yet. Im running the system pretty bare bones. I also should add that Im on bios version 1.20. I saw there are later releases but Im not sure if that could cause this kind of issue.

You may also want to try installing the 980ti and seeing if that gets you into windows. It could be a display driver issue (installed wrong during installation perhaps?). 

By your description, windows is throwing a fit about something. This is usually either drivers, memory or a device conflict. Given you are running a minimal config, I would say possibly memory. Try a single stick, if it fails try the other. 

If neither work, try checking your memory's specs and manually input the values in the UEFI, including voltage. This is a rather odd scenario. The power supply could be faulty and causing issues when under heavier load (windows startup can be fairly intensive). 

It's always wise to clear CMOS at least once when you have finished putting a system together, before installing the OS. 

Im running memtest right now just incase, I did swap out my ram a few times ( I have 4 sticks, only 2 installed currently an a2 and b2.

The system is stable in uefi, I was holding off on the bios update as a last resort...

Ill report back once memtest is done and I try some of these suggestions, you have great ideas I can already try here.

Ever since we moved from BIOS to UEFI this has been an important step. The UEFI is much more advanced and allows a lot more control but the down side is that it has a tendency of not clearing old settings when new devices are installed. This creates conflicting data that can cause issues. This is why it is always good to clear CMOS every time you make any significant hardware change. 

Does it matter that in the Bios, it shows me that the ram is seen correctly, cas timings and voltage, but in the ram display it shows 2133 instead of 3200?

I also noticed something else. There was a little strange silver screw in the box with my motherboard. I can see where it comes from, there are several holes on the board and in the two next to eachother in the center in the manual show screws, and one of mine is missing. Could that be causing any issues as well? I also noticed that one of my fan 3 pins is bent too, I know I didnt do that so Im wondering if this is actually a new board or not ( from newegg RMA) ...

My previous board didn't seem to have this issue but I still had the same problem so Im not sure if it is related to anything.

Make sure your power connectors are firmly seated and try reinstalling the OS again.

This one has me scratching my head a little. Stable in UEFI but not loading windows..... 

Thank you both, I really appreciate the time spent here helping me with this issue. I was feeling pretty alone / lost here and all the tips and support really helped. I wanted to let you know that it was in fact the power supply.  I replaced my old cosair 750 with a new rmx750 today and it booted up with no issues, plowed through the install and is running stable. 

This morning, I found one other rogue article where another person had the same issues, posting fine and stable in the BIOS but instant reboot when accessing a known good drive. This is apparently a good indicator that the PSU is bad. 

Again, I really appreciate your assistance.

Enjoy the build