Hello. This is my first time to post a PC-related problem of mine in a forum, and I'm pretty sure the people in this community are always willing to help. I'm also quite new to the PC environment, so please bear with me. 
Anyway, on to the problem. This is a custom build and I got this PC about a month ago. I was running on on-board graphics and all of a sudden, my PC just froze. I couldn't move my mouse and my keyboard was also not responding. I thought to myself, "Maybe it's just the lack of a graphics card". Once I got my graphics card, the freezing still persisted. Since everything was still under warranty, I decided to bring my PC to the place where I bought it from. I left it there to be diagnosed (they used memtest86, furmark and some HDD program checker) After a few days, they told me that there was nothing wrong. No hardware issues and it never froze on them while they were diagnosing it. With that said, I decided to get my PC back. Despite what those people said, it still froze on me as soon as I started using it again. Brought my PC the second time, they said the same thing. No problem whatsoever. When I got it back (from the second visit to the store), it still froze. The hard part about this freeze is that it happens randomly. It either happens when I'm browsing, playing games or even on idle.
At this point, I tried solving the problem myself. I tried turning off fast startup, running "sfc /scannow" on command prompt (no errors), updated both my BIOS and the drivers of my GPU. I also thought it was a hard drive issue, so I removed my SSD m.2 and my SSHD (I tried using both as a primary drive. Freeze still occurred.) I used my old hard drive instead. It still freezes. It doesn't freeze when I boot up in Safe Mode, though. I've tried running memtest86, furmark and prime95 myself just to see if the people that diagnosed my PC were telling the truth. Weirdly, the tests show no errors but it froze a few minutes AFTER I stopped the programs. Apparently, it doesn't freeze during the stress tests.
Hopefully, someone can help me with my problem. Thank you!
Specs:
Chassis: Phanteks Enthoo Pro M
Motherboard: MSi H170 Gaming M3
Processor: Intel Core i5 6600
HDD/SSDs: Crucial MX200 250GB m.2
Seagate Desktop SSHD 1TB
Seagate HDD 500GB
CPU Cooler: Noctua NH-D15
Graphics Card: Asus Strix GTX 970
RAM: Kingston HyperX FURY DDR4 16GB (8GBx2) 2133MHz
PSU: Corsair RM750
OS: Windows 10 Pro 64-bit
Anyway, on to the problem. This is a custom build and I got this PC about a month ago. I was running on on-board graphics and all of a sudden, my PC just froze. I couldn't move my mouse and my keyboard was also not responding. I thought to myself, "Maybe it's just the lack of a graphics card". Once I got my graphics card, the freezing still persisted. Since everything was still under warranty, I decided to bring my PC to the place where I bought it from. I left it there to be diagnosed (they used memtest86, furmark and some HDD program checker) After a few days, they told me that there was nothing wrong. No hardware issues and it never froze on them while they were diagnosing it. With that said, I decided to get my PC back. Despite what those people said, it still froze on me as soon as I started using it again. Brought my PC the second time, they said the same thing. No problem whatsoever. When I got it back (from the second visit to the store), it still froze. The hard part about this freeze is that it happens randomly. It either happens when I'm browsing, playing games or even on idle.
At this point, I tried solving the problem myself. I tried turning off fast startup, running "sfc /scannow" on command prompt (no errors), updated both my BIOS and the drivers of my GPU. I also thought it was a hard drive issue, so I removed my SSD m.2 and my SSHD (I tried using both as a primary drive. Freeze still occurred.) I used my old hard drive instead. It still freezes. It doesn't freeze when I boot up in Safe Mode, though. I've tried running memtest86, furmark and prime95 myself just to see if the people that diagnosed my PC were telling the truth. Weirdly, the tests show no errors but it froze a few minutes AFTER I stopped the programs. Apparently, it doesn't freeze during the stress tests.
Hopefully, someone can help me with my problem. Thank you!
Specs:
Chassis: Phanteks Enthoo Pro M
Motherboard: MSi H170 Gaming M3
Processor: Intel Core i5 6600
HDD/SSDs: Crucial MX200 250GB m.2
Seagate Desktop SSHD 1TB
Seagate HDD 500GB
CPU Cooler: Noctua NH-D15
Graphics Card: Asus Strix GTX 970
RAM: Kingston HyperX FURY DDR4 16GB (8GBx2) 2133MHz
PSU: Corsair RM750
OS: Windows 10 Pro 64-bit
