Please help! Can't access anything except bios!

[Nightscoming]

I believe I have a corrupted Windows file, at first it sent me to a blue screen where I could try different things such as resetting my computer to a specific date etc. But it's gotten worse, now it won't let me do anything. All it does is repeatedly restart with a error code at the bottom. All I think I can access is my bios. Please help! Error code is 0xc000021a

 

[Colif]

Bug Check 0xC000021A: STATUS_SYSTEM_PROCESS_TERMINATED

This error occurs when a user-mode subsystem, such as WinLogon or the Client Server Run-Time Subsystem (CSRSS), has been fatally compromised and security can no longer be guaranteed. In response, the operating system switches to kernel mode. Microsoft Windows cannot run without WinLogon or CSRSS. Therefore, this is one of the few cases where the failure of a user-mode service can shut down the system.

is there anything on C drive you want to rescue? try making this on another PC: http://www.howtogeek.com/howto/windows-vista/use-ubuntu-live-cd-to-backup-files-from-your-dead-windows-computer/
Also, on another PC, download the Windows 10 media creation tool and use it to make a win 10 installer on USB

if you can copy everything off PC you want to rescue, I would do a fresh install as windows isn't going to start from where you are

change boot order in BIOS so USB is first, hdd second
boot from installer
follow this guide: http://www.tenforums.com/tutorials/1950-windows-10-clean-install.html

when you reach the screen asking for licence, click "I don't have a key" and win 10 will continue to install and reactivate once finished

On the screen where you choose where to install win 10, if it gives you an error about GPT drives, delete all the partitions on the hdd and press next. If it still gives error, cancel out of the installer and restart PC and start installer again, it will accept next on that screen this time (some PC just need a restart here)

 

[johnbl]

would need the memory dump from c:\windows\minidump directory if you can get to it.
you can put it on a server like microsoft one drive, share the files as public and post a link.

it will have the error codes to help figure out why the process died.

 

[johnbl]

would need the memory dump from c:\windows\minidump directory if you can get to it.
you can put it on a server like microsoft one drive, share the files as public and post a link.

it will have the error codes to help figure out why the process died.

if your system is stable enough you can update the BIOS and motherboard drivers.
if the error code shown in the bugcheck has 0xc00000005 you will also want to run memtest86 to confirm your memory timings in bios are correct.