[SOLVED] PC shuting down and rebooted itself while playing Final Fantasy 14 and Dark Soul 3


Jun 13, 2013
Hi, I wonder if anyone can help. I don't know which forum to put this post so I try component. I have built a system for my daughter some years ago. Spec here:
Gigabyte Z68XP-UD3P
i5-2500KS with Noctua D9L CPU Cooler
1TB Samsung SSD
1250W EMAX ERV1250EGT 85 Plus
CMaster HAF 912 mid-tower case
External WiFi adapter

The system was upgraded to the above spec 3 years ago and given to her for her degree course. Was running fine until last week. She said she was playing Final Fantasy 14 online and the system just shutdown and rebooted itself. She had reinstalled Final Fantasy 14 but the problem still remain. I asked her to install the latest GeForce driver. It was on ver 432.xx when she contacted me last night (her university is about 3 hrs drive away). I had also asked her to do window update and it was done to the latest one. But the problem remained. So, I asked her to test other games. She tested Dark Soul 3 and the same thing happened. The PC just rebooted. I worryingly suspect that there is hardware problem as she mentioned earlier that her place was so hot and no one in her residence has any fan of any sort!!! While she was not playing game, she used the PC for Adobe Premier which is for her course. She said she didn't experience such problem when using Adobe Premiere. I thought Premiere is more demanding than Final Fantasy 14 and Dark Soul 3. So, does anyone has any idea where should I look next?
At the moment, I am worrying that if any hardware has been damaged by overheat problem. But the Nautua fan is very reliable. I have just texted her to see if any of the CPU and GPU fans is showing fault. Still waiting for reply.
Can any malware cause such problem? Your suggestion is much appreciated. Thank you in advance for helping.

PS I bought and installed the external WiFi adapter when I delivered the system to her place and found out that her room was more than 10 M from the router. She was sharing with two other students. I just cannot remember what brand and model was the adapter.