Question Newly built PC freezes randomly

[MarbleSheep]

Hello there!

First of all, I apologize if I posted in the wrong sub.

So I got my first ever PC built for me a month ago and since then I've been having this weird issue where the whole system freezes. Just like a frame freezes and the fraction of any sounds in the system remained. Needless to say it happened during the games, web browsing and working in UE4.

At first I wasn't sure whether that was an issue with Windows 10 or the motherboard. So I did a memory test, system test and found out in the log that I had corrupted Windows files. After reinstalling it the issue remained. So I did all the possible solutions I could find on the web including: turning off C states in BIOS, Power settings for SSD/HDD, Resetting BIOS to it's default state, downloaded latest drivers for the hardware & Windows.
After setting BIOS to default settings I haven't had any freezes so far. However I still think it's gonna freeze on me at some points. My question is - is there a name for this particular issue? How would I approach fixing it?

Thanks in advance!

EDIT: here are my specs
https://www.userbenchmark.com/UserRun/20166667

 

[vapour]

what psu, have you checked CPU/GPU usage/temp? Antivirus?

 

[MarbleSheep]

GPU/CPU are not heavily loaded during games/applications and their temp is alright. GPU can only get to 79 degrees C max and I don't use antivirus.
EDIT: PSU is Seasonic M12II Series M12II-620 Bronze - 620 Watt