Why does Windows 8.1 freeze and the hard drive freezes?

Question

Hard disks

The other day I was building a new computer for a friend. After assembling and installing the OS (the choice fell on Win 8.1), we noticed a malfunction. In the course of normal work at the PC, everything suddenly stops, the hard drive also stops working, but the screen is on. If you restart the PC via "reset" on the case, the car does not start the first time, and sometimes not even the second time.
What was done to identify the cause of such a freeze:
1. Updated all drivers
2. Antivirus check. Detected a lot of trojans, including on a new hard drive. Removed(?).
3. All other possible problems with iron are excluded by stress tests aimed at individual parts of the entire system. (Although the HDD under the benchmark behaved well)
4.The disk settings were checked, but nothing was found there either.
5. We monitored the temperature, everything is also in order.
PC Configuration:
Power Supply: THERMALTAKE TR2 TR-630PCWEU, 630W
Video Card: PCI-E 3.0 ASUS Radeon R7 260X, 2GB, GDDR5
Hard Drive: 3.5" WD Caviar Blue WD5000AAKX, 500GB, SATA III
Motherboard: ASUS SABERTOOTH 990FX R2.0 SocketAM3+, ATX
Memory module: CORSAIR CMV8GX3M2A1600C11 DDR3- 2x 4GB, 1600, DIMM
Processor: AMD FX 8350, SocketAM3+
All parts are still under warranty, but of course I don't want to bring it to a replacement either.
According to the PC owner: "It was about 30 minutes everything is okay, I listened to music and dug. Decided to download the torrent. Downloaded. I started to install and suddenly, as the muzzle groaned, the mouse stopped and ********. Simply, without doing anything, he gives out such hell. ".
Next, we plan to replace the power source. Instead of a thousand adapters and tees, we will install a pilot.
Plus, the owner asked to change the OS to Win 7, referring to the fact that he does not want to learn how to work with the new OS. (I hope it helps)
The "client" is not satisfied , and my ideas are almost exhausted, I hope for help.
UPD # 1
A colleague shared with the same experience. Says "after the rollback of updates to W8.1 everything became fine."
UPD # 2
Replacing Windows did not help. The same thing started after installing some software and
drivers.UPD#3
Bios update didn't help. Installed the OS on the old HDD, on which everything worked, did not help either. More and more I tend to neglect the consumption of food.

Answer 1

I personally ALWAYS turn off auto-updates. I just put a clean distribution kit with the latest available joint venture. Well, that's how I like it, but there are no "sides" due to the next update and there are no strains on slow computers when installing a bunch of updates "Do not turn off the computer is being updated", not everyone tolerates this and often turns it off stupidly, and then they scream as everything suddenly stopped work.
Try to do the same with win8.1 on this machine.

Answer 2

Update the motherboard BIOS to the latest version.
(And don't confuse BIOS with drivers.)