Question Weird intermittent temp issue

[Fardale99]

So having trouble troubleshooting an overheating issue.
On a particular day, when I updated my windows and cleaned out my computer (makes it even harder to diagnose issue) a problem started occurring.
Basically, SOMETIMES (but still too often), on startup my MSI shows that my HD0 temps are increasing up and past 100CEL!! (at which point I turned it off)
Speedfan on the other hand shows the temp going up and around 70-80C and my cpu core temps sitting at around 50. Fans and BIOS temps all agree with this. (sometimes happens in BIOS too)

While this is all happening everything else is idle. No high cpu usage, no disk usage no nothing.
Restart the computer until the problem... stops. I can game no problem, watch vids multitask. highest temp is gpu at 70ish for intense games while all other temps are normal. 15C for cpu at idle...

The real issue that makes me nervous is when it starts doing this when my computer needs to restart and update. I don't wanna turn it off and mess up the update but I don't wanna leave it on incase its burning to death.
Again, if i startup and there's no issue, I can leave it on and use it all day for gaming and its fine (which makes me think the fans/paste etc is all fine. It doesn't move so....
This has been happening for few months now and no idea how to fix it.

Any ideas would be great.
Thanks.

edit: can't actually feel any crazy heat coming from fans when this is happening but I can while gaming so i'm sure the cooling is fine.

Windows 10
Intel(R) Core(TM) i7-9700K CPU @ 3.60GHz 3.60 GHz
Zotac GeForce RTX 2070 Mini 8192MB GDDR6 PCI-Express Graphics Card
Gigabyte 256GB M.2 PCIe x2 NVMe SSD/Solid State Drive

 

[Ralston18]

PSU: make, model, wattage, age, condition (new, refurbished, used)?

 

[Lutfij]

Welcome to the forums, newcomer!

What BISO version are you currently on for your motherboard? What version of Windows 10 are you on? It seems to me that you might need to reinstall the OS, sensing that you might be suffering from memory leak, no matter what the www says, restoring, SFC or reset's don't avert this issue. You will need a clean reinstall. You should refabricate your bootable USB installer using Windows Media Creation tools.

Make and model of your PSU and it's age? How are you cooling that processor? Make and model of your chassis and it's airflow in said chassis? Might want to also attach images of your build in case your cooling/fan orientation might be wrong.

 

[Fardale99]

OS Name Microsoft Windows 10 Home
Version 10.0.19042 Build 19042

System Manufacturer Gigabyte Technology Co., Ltd.
System Model Z390 UD
System Type x64-based PC
Processor Intel(R) Core(TM) i7-9700K CPU @ 3.60GHz, 3600 Mhz, 8 Core(s), 8 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. F3, 29/08/2018

Can't find PSU info at the moment, it's buried under an extra layer of screws. thought I had a screwdriver handy...
The whole system has just turned 2 years old, but this problem came on very suddenly. Because of this and the fact that its intermittent at startup I was assuming it was a memory problem too. I tried to do a system restore at the time but I could here the fans going crazy while it was doing so and this put me off a complete windows reinstall.

Edit:
Case: Phanteks Eclipse P350X Glass Digital RGB Midi Tower Case

 

[Fardale99]

cooling sytem is typical fans and sink. its an overclockers uk machine which was working great for ages (and most of the time still is). The cpu fan sink is linked up to fans at the front of case.


Swear I cleaned it somewhat recently lol

 

[Fardale99]

I understand OS/BIOS are the likely two solutions to cover a problem like this, but I was hoping to avoid these as, as I said before, I'm worried that it will overheat in the middle of the OS install (and I just plain hate updating Bios. paranoid city).

Was hoping for alternate ideas before I bit the bullet.