Troubleshooting PC problems - Constant restarts and rattling noise.

[Anakso]

I've been having PC problems for a while now, I won't be able to afford a new build or even upgrading any of the more expensive parts for quite some time unless I really have to.

Problems been persistent for about a year now, I'm hoping it's the HDD or RAM as it won't be too difficult to replace them.

The restarting.
Previously, my PC was blue screening and having constant driver issues with the GPU, after reinstalling the driver many times I think this problem has gone. No blue screens or driver issues in a long time. Now it's just restarts. Usually this happens while I'm away from my computer and if my computer is in sleep mode (which I've started having to do because of the rattling noise) then sometimes it just won't boot up again when I move the mouse and I have to turn it on. Today it restarted while I was browsing imgur and it was basically the same as if I hit the restart button.

Rattling noise
Not sure if rattling is the right description but it's the most accurate thing I could think of, it's constant but generally quite and intermittent (like two rattles every few seconds) that's what's happening now, occasionally it will grow loud and become none stop though. That happens if I start loading something big, If I were to close down my browser and then open and restore session it would happen for example it would happen but other times it will happen randomly (like while I'm trying to sleep)

That's basically all I have to go on, my computer is over 3 years old now I believe. The only part that has been replaced in that time is the GPU which I replaced with a cheap GPU due to a fan on my old one breaking.

Not sure how relevant my build list is but it can't hurt, not sure on the specifics on everything but here is what I can remember/find easily.
CPU: i7-2600k 3.40GHz
RAM: 8GB DDR3
OS: 64 Bit Windows 7 Home Premium
GPU: AMD Gigabyte HD 7790
HD: 1TB WD Black (if memory serves)
Mobo: ASUS P8Z68-V PRO

If there is any troubleshooting I can do to narrow the problem down further short of buying a new HDD and seeing if that fixes it please let me know.

[Denpepe]

Open the pc up and listen to where the noise comes from would be my first tought, could be as silly as a cable to close to a fan or could be a dying HDD

[Anakso]

Done, thanks. The noise is definitely coming from my HDD and no cables are hitting any fans.

Does a hard drive making a noise like this mean it's dying and could such an issue also be causing the restarts or are these two separate problems?
If the answers are yes and yes then good I can replace my HDD and problem solved xD

[Onikame]

I think it is your power supply. With a crashing disk I would expect more blue screen than restarts. Check if the capacitors in it are of good quality. Else it might cause fluctuations that in turn can cause restarts. This might also cause BSODs that solve itself or other problems that just pop up randomly.

On driver problems. Also disable any software that might overclock your GPU, like GamerOSD, SmartDoctor or Afterburner. That might also do something.

[Anakso]

http://www.newegg.com/Product/Produc...D=qwapsh8sfjib

This is my PSU, not sure how to check if the capacitors are good, going by the reviews no one is mentioning this kind of problem. Some people mention it dying after a while but by that I assume they mean totally dying.

I don't have any overclocking programs.

[Denpepe]

Check this out to see if your HD has problems