Random BSODs with various Stop Codes

Hi all, I'm new here, and fairly desperate, so I hope you guys help!

After a year or so of fairly stable computing, my PC has started getting random BSODs during use or even while idle. I noticed this started happening after my PC failed to boot one day (but suddenly managed to start up an hour later), and after I removed some hard drives from the system.

I've been getting different Stop Codes as well:
- 0x000000F4
- 0x0000007A - KERNAL_DATA_INPAGE_ERROR (msrpc.sys)
- 0x00000050 - PAGE_FAULT_IN_NONPAGED_AREA (win32k.sys)

But everytime the BSOD happens, it stops at "initializing disk for crash dump", so I don't have any minidumps to share I think.

I've ran chkdsks and the Windows Memory Diagnostic says my RAM sticks are fine. HD Sentinel says my hard disks are in Perfect condition as well. My PC BSODed during a virus scan, but I don't think that should be the issue. I'm currently testing RAM sticks by removing one, and leaving it idle. I've also attached the information from the SF Diagnostic tool.

Let me know if there's any information I can give to help the diagnostic along! Thanks so much!

EDIT: I noticed EventSys.txt has the message "An error was detected on device \Device\Harddisk7\DR10 during a paging operation." But I've only 3 harddrives (SSD + 2 data drives) at the moment. So how do I determine which is Harddisk7?

I'll try that later today.

But why would the problem occur all of a sudden when it's been working fine for so long?
Especially since the latest firmware isn't recent either.