Blue Screen Of Death Every Other Day, Memtest Fine

4 hours of memtest is far from enough to rule out faulty ram. I would either let it run for up to 24 hours or remove one stick at a time and see what happens. The latter is usually the more sane test as you probably don't want your computer inaccessible for a long period of time

You change any USB-connected devices recently? Only BSODs I've ever gotten is from USB bus failures, but my GPUs are all AMD.

If you're getting blue screens, are you getting dump files? You can get WinDBG from free on the Microsoft store, run !analyze on the dump, and it can tell you exactly what's causing it.

If you're not getting dump files, but you're set up TO get them (I think by default Win10/11 does small memory dumps on BSODs) then it's more than likely the firmware on your SSD/NVME as it's crashing too quickly to make the dump file.

Regardless WinDBG and a dump file will point to exactly what's happening.

Gotta start removing stuff assuming you didn't install to much driver in this timeline

Pop in an older gpu
Take a stick of ram out something

You did only run memtest for a short period
Run it overnight from a USB or something no os

Are you using Atmos?

I ran into a ton of problems with graphics drives and atmos when I set up my new system. I think it was an MSI problem (dynamic IRQ assignment) (I was also dealing with EDID issues on top of it - and there might have been a 3rd issue too, took me months to get it all settled)

Just had an issue, turn out I had to reset the CMOS battery. If you dont know how to do, just remove the power cable of your PC. Hold power for 30 seconds, then release; replug, and restart.

I am not trying to be adamant this will fix the issue, but cant hurt trying.

If you cloned the SSD, this is a perfect opportunity to rule out software entirely. Create a USB with the latest driver installers direct from the manufacturer of your equipment- cpu, gpu, motherboard, network etc. Wipe the new SSD and do a clean OS install the fresh drivers and start adding apps. If the problem still happens, you can be confident it’s hardware. If it disappears, you’ve fixed it.

Running a system for long stretches without rebooting (only sleeping) can make software instability more likely, so starting fresh will help eliminate that as a factor.

If it turns out to be hardware, and you aren't approaching 90C in your CPU or GPU at any point, alternate testing one RAM stick in the correct slot (look this up per your motherboard manufacturer's documentation), the next likely culprit is the power supply, if the power supply is failing it could give the same symptoms of pulling a component temporarily while the computer is on, which is never good. But start with the clean install if you haven't— it’s the fastest way to split the problem into software or hardware.

If you've changed any BIOS settings, reset everything to default in the BIOS before during a clean install.

This thread is 99% snake oil selling, 1% "try everything until something magic happens".

Motherboard dying?

Did you replace your ram yet?

What kind of CPU are you running again?
Include the model

Fresh paste and some compressed air action.

But it is 5 years old. If it weren't for anything after 12th being a trainwreck it'd definitely be upgrade time.

Also. 16th will be delayed, plus 100% tariff. Better get that cpu working or pull the trigger immediately. Or you'll be paying a grand for mid/high in 2026. If intel doesn't go bankrupt. and it'll run on 1000 watts.

Buy used server cpus. Cheaper and better than their desktop parts. Check your mobo for compatibility.