Question PC Frequently Freezes Or Shows Death Screen

[JohnnyP159]

I've been using my PC for quite a while now. In the past year or so my PC started acting very weird.
It's been either showing the blue screen, freeze with a sound of a looping sound, freezing with a flashing square with tiny random squared colors at the top left of the screen, or just freezes after I leave the computer for a while.
One of the additional problems I get once in a while was a black screen with on of the lines saying "One of your disks need to be checked for consistency. You may cancel the disk check, but it is strongly recommended that you continue" and it would run some kind of check on my computer.
I tried restoring my computer twice and it keeps on acting like this.
Due to it giving me that screen where it checks my C Hard drive, I assumed it's related to my drive. Therefore, I bought a new SSD, restored my computer and moved my operating system/Windows to my new SSD, making the previous HDD as an additional drive for storage.
After doing as such, I keep on getting such errors and problems and I don't know what to do! I'm exhausted because I can't find a fix and I'm assuming it's from of my PC components but I can't figure which one!
I tried running SFC /SCANNOW command and it showed that I don't have any problems in my drives.

These are my specs:
Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_ldr_escrow.190220-1800)
Language: English (Regional Setting: English)
System Manufacturer: Gigabyte Technology Co., Ltd.
System Model: P55-USB3
BIOS: Award Modular BIOS v6.00PG
Processor: Intel(R) Core(TM) i7 CPU 860 @ 2.80GHz (8 CPUs), ~2.8GHz
Memory: 12288MB RAM
Available OS Memory: 12284MB RAM
Page File: 3939MB used, 20625MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
Card name: NVIDIA GeForce GTX 1050 Ti
Manufacturer: NVIDIA
Chip type: GeForce GTX 1050 Ti

Please help, I've been trying to work it out for more than a year and it's really exhausting...

 

[geofelt]

What might have changed since all was well?

Try removing the suspect HDD from your system and see how you do.
I have had a case where a corrupted HDD just being present caused problems.

12gb of ram suggests a mismatched set of ram which can cause problems.
As a quick hardware test,
Run memtest86.
It boots from a usb stick and does not use windows.
You can download the free edition here:
https://www.memtest86.com/download.htm

If you can run a full pass with NO errors, your ram should be ok.

 

[JohnnyP159]

I don't recall anything changing since then.
I'm trying the memtest method, though when I try booting it from usb it get's stuck at "Loading Operating System". Tried looking for a fix and couldn't find one. Any help?