hm, whenever one of my PSUs died I could tell that by a strange metallic smell comming from it

It's not dead. It seems to work fine, there is no strange smell etc. I just think that it tries to power itself off when it's about TO die. Isn't there an option to untick that box and let it continue even if it nears the meltdown? Because I am tempted to activate it, although I'll probably be held liable for the damage it will cause :p.

How hard is it to change the PSU? I've spoken to the engineer from the company and he said it wont have an effect on the warranty as long as I don't bugger up the other components in the proccess - ie if it works fine afterwards for few weeks, then I am in the clear.

Changing the PSU is pretty easy. It's a large, separate box, well away from any delicate components. You just have to unplug the power cables, unscrew the power supply from the case and take it out. Worst case scenario is that you drop the PSU onto delicate components. There are a lot of plugs leading from the power supply, so memorise how many there are, just in case you forgot to plug in the hard drive or something and you get a boot error message.

Haha yeah I know what it is, I was just thinking of the possibly complications of having to change it, but it is separated from the rest by a good margin, but then again, I have butter fingers. Slip, poof goes the motherboard. I honestly think its the PSU fucking me atm, as everything else seems to be working fine - maybe the graphics card is too much for it? 

I mean jesus fucking christ 750w for £14.99?

 http://www.amazon.co.uk/Alpine-750Watt-PSU-120mm-Retail/dp/7135799380/ref=sr_1_1?ie=UTF8&qid=1340735717&sr=8-1

Not suspicious at all.

It's very unlikely that you will drop it, I usually grab it by the cables for extra grip.

Yeah, it does sound like a weak PSU problem, especially as games increase the power draw from the CPU and GPU and your computer decides when it wants to turn on. Cheap PSU's never supply the amount of power they say they do, I'd be surprised if it even supplies 350w. It angers me that the company you bought it off optionally put shit like that into the computer, they save £30 and for most people it will break just outside of warranty.

A good PSU isn't that much more money, the extra system stability and surge protection is worth it. Don't ask for a replacement from the company.

Never heard of that PSU, wouldn't trust it to deliver steady 750w of power. Your system would easily run on a quality 500w.

You should never skimp on PSU, it's the most important part inside and it being poorly built can cause damage to other hardware inside the case.

yep get a new and better PSU, for example a decent brand like BeQuiet. Will be much more expensive than that 15 pounds PSU you showed us, but still cheaper than buying multiple trashy ones and especially buying a new motherboard when your PSU bites the dust (happened to me).
500w-550w should be enough. Expect to spend around 50 pounds.

Sounds like PSU overload to me.

In order to maintain a decent lasting PSU (and generally more efficient), it's generally recommended that you get one that's twice the power rating of the components that it powers.

Get an XFX Pro850W Core Edition. That thing is badass.

Also, never ever EVER skimp on your PSU. EVER. My dad did when he got me one for Christmas and it almost fried my graphics card.

Always go with a trusted brand. Corsair is pretty phenomenal.

I am going for the Corsair one, I think I will send it off to them to highlight the problem, and make SURE that it's the PSU, I will ask specifically what the problem was, and if it was indeed the PSU, I'll be changing it for about 500-750W corsair one I think. I can tell that the PSU actually brings the rig down drastically. And the last few days performance really shows it. I am disappointed they've decided to put that in there, and if they wont do anything about it, I still haven't given them a review on eBay, so many a 60-70% instead of the usual 100% will give them a wake up call in regards to the PSU.