Windows 10 errors, then many other issues followed. Help!

[Ieuan]

Okay, so where do I begin.
I came home from college on the 7th of Dec, to find that my PC's power supply switch was set to Off. I switched it to on and then proceeded to boot my PC (Windows 10). After booting, I was greeted with my desktop as I would expect, then the screen went black. I realised after a couple of minutes that something was wrong, and then opened task manager and opened the explorer process. I had my desktop and taskbar back. Then the problems began.
After trying to open the windows menu by clicking the windows logo and it not opening, I tried accessing the files I wanted using the windows explorer instead. After that I got a blue screen with the 'Critical Process Died' message. Having had a couple bluescreens before, I rebooted and hoped for the best, and after the computer spending about 20mins to repair itself, the bluescreen came back. Same message. I then proceeded to try all of the options such as reverting to an earlier build, running diagnostics, and so on, but the error persisted.
After trying my best to solve it, I decided that I would reinstall windows completely. I formatted my hard drive, and then managed to install windows 7 Ultimate (don't ask how). I had an issue with the keyboard and mouse not registering on the profile creation screen, but solved it by enabling legacy usb support. So windows 7 was installed and everything seemed fine. I then downloaded the windows 10 media creation tool, and tried upgrading my pc. Alas, "Windows 10 installation failed". So instead I grabbed an 8gb USB pen drive, and tried creating installation media onto that. That also failed.
After doing some research, I found that I was able to make the UsB an ISO image of windows 10 install, and used Rufus to accomplish that.

So, today, the 8th of Dec, I came home and tried my USB ISO method. Yet the PC freezes at the POST screen, and I am not able to use my keyboard to access the BIOS, and therefore can't install Windows 10. I managed to boot the previously installed windows 7, and that's where I am now. Help me please.

Obviously Christmas is coming and I have an rx-480 and new psu coming that I would like to be able to use... I appreciate all help and comments. Thank you !

Specs:
i5-6500
Amd HD-7850
ASRock combo-G H110M
8gb 2133 DDR4 Ram from Kingston

 

[bajgur]

so now your PC stuck at POST, right?
try unplug your HDD/SSD and clear CMOS, see if it can get you to BIOS/UEFI.

 

[festerovic]

Data usually gets corrupted and exhibits these problems when the RAM is bad (or timed incorrectly) or the drive is bad. To check the first, download and create an ISO for memtest86 (or maybe a later version, havent used it for a while). Run this for about 1-2 hours and make sure it completes at least 2 cycles. Only use 1 stick of RAM at a time to test with.


If you can, try a new HDD or better yet SSD to install windows on, for test purposes.

I might not trust the media that you used to install windows with if it was created on the same computer. Maybe download and make new media on a different computer.

 

[Ieuan]

Somehow, I have managed to solve the problem.
I came home about 2 hours after this thread was posted, and then proceeded to reboot the computer. Lo and behold, I could use the POST screen to access the BIOS. After that, I rebooted a couple of times and my Windows 10 ISO USB was detected and I was able to reinstall.

However, I am very happy that I received replies so quickly and my thanks go to you for trying to help me solve this problem. Thank you!