Hard Drive cutting in and out randomly/disappearing

Jkhoward yes my PSU has 3 and i tried each one, its a brand new Seasonic 620W

Drtweak the status came up as good.

Iv also done a memtest

As stated iv already tried a different motherboard, hard drive, and cables. CPU came out of a previous computer that didnt have any of these issues. CPU is about 5 months old, rest of the computer is about 3 months old.

2201 But I did have the exact same model with the 2501 bios installed before and still had the exact same problem.

MY OS is 8.1 and I did load into safe mode and it didn't do it. but that doesn't really prove anything because i can go a week without having any problems. Then all of a sudden it may do it 5 times in one day. Every time it happens though the hard drive LED stays solid until it either works itself out or crashes. Plus id assume safe mode isnt near as much stress on the system so it may never do it. It is most likely to happen whenever I click on something to open. Also it seems to happen less frequently after the computers been turned on a while. Its more likely to happen whenever I have just turned it on. Also it seems to do it more frequently whenever multi tasking with the internet browser opened.

I do play guild wars 2 often and it has never crashed or locked up during gameplay. It runs like a perfect computer. but if i play a game like sims 3 (with all expansions) it almost always will randomly crash. Ill go to get a drink and come back to find my computer has rebooted itself.

I already have a program that shows me the dump files and error history. No errors recorded that relate to my problem. I had a driver error that caused a blue screen but that problem has already been fixed, i shall follow your steps and see if it gives me any errors during future issues but more often then not the computer just refuses to load anything anymore and i have to manually hit the restart button to get it to reboot. thats when the hard drive no longer shows up in BIOS and i have to again manually restart and it shows up again and all goes back to normal. This problem has been frustrating me for many weeks. As no errors are produced and its hard to determine the source. its the equivalent if you were to just unplug the SATA cable.

Iv reinstalled windows. iv redone the drivers. I have taken my whole computer apart, cleaned, and reseated everything. Iv tried a different motherboard, cables, and hard drive. I have done hard drive testing, Prime95 and memtest. No errors whatsoever. Also note the components are not even half a year old, the oldest component is the CPU and i got it back in February so its by no means considered old.

What confuses me is the only thing i havn't replaced is the CPU and but the previous computer it was in didnt have any of these issues.( i havnt replaced the GPU either but its been tested in another computer and its working fine) Is it possible my few month old CPU is already starting to fail? Even though it handles prime95 stress testing just fine? Im always very gentle with my hardware and i am always sure to ground myself before handling any of the internals. The CPU is the only part not under warranty so i dont plan to replace it unless i am sure its the cause. I have a hyper 212 evo cooler and the CPU never goes above 50 degrees during heavy gaming so i know it hasnt been damaged due to overheating. during prime95 max heat stress testing it usually goes up to about 50-55 degrees and stays there.

Also i did some exploring and my motherboard has 3 modes. power saver, standard, and optimal. When i turn on optimal it causes the problem to happen more frequently.

Well i managed to get a blue screen finally instead of it just shutting down/restarting.
it came up saying "critical process died" but it didnt put anything into the dump files so no way to check exactly what was going on during the failure. probably because the hard drive tends to cut out during this time. I Have updated my drivers and have reinstalled windows but that didnt fix it. I am beginning to suspect CPU is faulty because it seems to be clear that the hard drive itself is not responsible. I have tried multiple hard drives. but any input/advice is appreciated.

I know this is old but i wanted to come back and post the solution.

Summary: All the WD drives I received were indeed faulty. Buying a Seagate fixed all problems.


Details:

I went through 5 western digital hard drives to fix this issue, mind you i did heavy testing with each. I had called western digital and they told me there is no way i received 5 faulty drives in a row and it must be my computer that is the problem, they said they don't want to send me any more drives, and I agreed with them. After many thorough tests of each and every component i found no errors or problems(i used a hard drive from a different computer to do these tests). So i called them back and told them and so they just gave me a refund because it seems suspicious my computer would run fine using a non-WD hard drive as the boot drive.

I went out and bought a Seagate barracuda 1TB, I still had my suspicion that it was the hard drive even after WD assuring me that theres no way all 5 WD drives i had were all faulty, but they agreed to a refund and I went and bought a Seagate. So of course, I again do a fresh install of windows and I have been running a few weeks without a single issue. no freezing or slow downs, no random restarts or blue screens. I put my computer through everything that would have normally caused it to act weird and it never missed a beat using the Seagate.

Turns out all 5 western digital black drives were all garbage. WD wont admit it and claims my computer killed them. Which i know is false because i had multiple hard drives in my computer, alongside the WD drive, for months that never had a problem. The Seagate fixed every issue and is even outperforming all the WD black drives I had so far.

Thanks to everyone that tried to help!!