Question Windows not starting after crash

[HarvestBirdy]

Hello,
So windows isn't loading/starting, my computer is only booting to the BIOS. A few days ago I was watching a video while waiting for AVG Security to finish a deep scan when my PC froze. After a couple of seconds, I got the blue crash screen with the sad face and my PC rebooted. However, when it rebooted it went straight to the BIOS and since then it will only boot to the BIOS and won't boot up windows.
The BIOS doesn't show partition 1 of the hard drive hard drive I have windows installed on as a boot option and or in the boot override list. It does show partitions two and three of the OS drive.

Before the crash, I had three problems which I am not sure are related to this, but I figured I would mention them anyways in case they are linked or might help diagnose the problem.

1. Task Manager would crash. Initially, it would close a few seconds after I opened it. The next day Task Manager would open, but when I pressed the option for more details (such as seeing Processes, Performance etc) it would instantly close.
2. When scrolling through my programs list it would also close on me. Sometimes I would only get halfway through the list, and other times all the way to Z before my mouse cursor would turn into the blue loading circle and then the programs list would close.
3. Notifications to scan my drive for errors from Windows, and then to restart my pc to fix drive errors once the scan was done. I did the scan and restarted. But two days later I got the message to scan reappear. So once more I did the scan and when I got the message to restart my pc to fix drive errors, I did so. But the next day, I got the scan message pop back up again.

These problems occurred together over the space of a week and were still going on on the day of the crash.

I have only been using windows 10 since May when I updated from windows 7, and until now everything has been working fine. This is the first time it has crashed on me and windows not booting up so I really don't know what to do. I would appreciate any help.

 

[Lutfij]

Please pass on the specs to your build like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:

include the age of the PSU apart from it's make and model.

 

[HarvestBirdy]

My specs:
CPU: Intel Core i7 5960X
Motherboard: Asus Rampage Extreme V
Ram: 16GB DDR4 RAM Corsair Dominators Platinum 3000 MHz (x8)
GPU: Nvidia Geforce RTX 2080
PSU: Corsair CP-9020140-UK HX1200 1200 W 80+ Platinum Fully Modular
Storage: 3 HDD's
OS: Windows 10 Professional 64 bit
CPU Cooler: Noctua NH-U14S with NF-A15 140mm Fan
Ram Coolers: Corsair Dominator Platinum Airflow Memory Fan (x2)
Capture Card: Avermedia HD Capture GC573 Live Gamer 4K

 

[HarvestBirdy]

To give an update, I have tried using Start-up repair from the USB I had the windows 10 installation media on and it said it couldn't repair my pc.

So I unplugged my two non-OS drives as I was preparing to do a reinstall of windows 10.
But when I booted and went to the BIOS, partition one of my OS drive was now appearing. I exited the BIOS and windows loaded.

I let it start up and after a few minutes shut the pc down. I plugged the other two drives back in. I stared my pc back up entered the BIOS and partition one of the OS drive was still showing. I exited the BIOS but all I got was a black screen. I left the pc for two minutes but windows didn't boot and the motherboard showed code Ad.
I restarted my pc and went back into the BIOS to find partition one of the OS drive had disappeared again.

I really confused as to what is going on.