Specs: p67 extreme4 gen3 i5 intel (Honestly can't remember much about it) 2x4 gb ram for 8 total. gtx 1060

I recently built a new computer and I was hoping to pass my old computer down to my son. I had to take the video card out and use it in my new system while waiting for my new card to arrive. The video card I had died so I found a replacement on FB marketplace. I put that video card into my NEW rig and ran it for about a week until my new video card showed up.

In this time I had only done some minor things on my old pc... like grabbing files and checking some information that I forgot to save. Eventually, it became time to reset the computer so I could pass it along.

During the installation of preparation for installing windows I started running into problems. Every time the computer would get to the point it was time to reboot it would crash, but still reboot. After a while the installation finished and actually seemed to work fine.

While in windows I started to get BSOD "Kmode exception" which almost instantly causes the pc to reboot.

Here's what I've tried...

first I went into bios and reset all the settings

Checked all drivers (including cpu and chipset)

I reinstalled windows and it had maybe only one reboot error.

I cleaned out the pc physically and used compressed air.

I disassembled the PC and plugged the components in one by one.

I tested each stick of ram one at a time in windows.

I took off the cpu cooler and reapplied thermal paste (had to be about 7-8 years).

Basically just re-did nearly everything I could think of but to no avail. The pc still boots and runs fine except for the BSOD and one other thing I noticed...

when I open task manager and go to performance the CPU speed is set to the standard 3.? GHZ (Sorry, I forget the exact clock) but the task manager will show me the current utilization at 100% (no matter what) and the GHz clock speed jumps in the millions and doesn't stay constant. It usually reads something insane like 2349822358 GHz which is obviously wrong and the number just keeps jumping around.

Without another i5 chip is there any way to troubleshoot and determine if it's the motherboard or the chip? I imagine it has to be one of the two since I feel like I've eliminated all the other possibilities but maybe I'm missing something?

Thanks in advance for any tips or thoughts. Seems rediculous that I now have a perfectly good video card sitting in a dead PC while my son games on an alienware :(

edit: latest dump I could grab

http://s000.tinyupload.com/index.php?file_id=34460482812503278689

edit 1: task manager

https://imgur.com/iuzGWDQ