[SOLVED] PC is crashing with "system thread exception not handled"

Jan 4, 2020
Thank you VERY much in advance to anyone who could help me!

Simply my PC is crashing to a blue screen with the message "system thread exception not handled"

It started yesterday, just 30 minutes after I downloaded and installed the Xbox Game Pass Beta APP for PC. To be more precise it started while I was downloading Halo or when the download finished. The PC was crashing from Desktop, I wasn't even launching the game!
I went to bed and this morning I unistalled Halo and closed the App. The PC was ok at that point and so I thought to give it another shot: I launch the installer for Halo and I went to lunch. When I came back the PC was stuck on Bios start page. I had to restart it manually. I finally unistalled Halo again and the things were going ok.
Then a couple of hours later I decided to play Gears 5 on Steam (which I played smoothly yesterday before installing the Xbox App) and after 20 minutes of gaming, with my big surprise the PC crashed again with the same error! I restarted it manually and I unistalled the Xbox App and closed TAV which is a software I've installed before the Xbox App (but also before the first game on Steam with my friend, so I was excluding it). I restarted Gears 5 on Steam and I got the same crash again. I quitted the game and I got the same crash again 2 times on desktop, not even playing. Now I've unistalled TAV too and the things seemed "stable", but then after 20 minutes it crashed again.. So it's not this.

I ran DISM.exe /Online /Cleanup-Image /RestoreHealth and sfc /scannow and things were ok. My bios is updated, I ran Malwarebytes and Avast (which is always active) and I've got no problems (generally I should be safe). I also got the latest driver for GPU.

Can someone help me please?

Thank you VERY much again!

CPU: Ryzen 2600x six core 3,6 ghz
Motherboard: Gigabyte b450 AORUS M
Ram: 16gb DDR4 channel : dual
SSD/HDD: KingSTON SA1000M8240G (OS) + 1 hybrid, and 1 ssd
GPU: NVIDIA GeForce 1070 GTX
PSU: Thermaltake Smart SE 730W
Chassis: ---
OS: Windows 10 Pro 64 Vers. 1909

BIOS version: Latest
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