Hey, I recently bought 2 HD 5750 card and i installed it on one pc and it works perfectly but when i installed it on my other pc there is a clicking noise coming from my hard drive. I have i identified the clicking noise definitely coming from the hard drive. When i try booting up nothing comes up just a clicking noise from the HDD. I tried starting the pc up with my old graphics card and it works perfectly so im a bit confused. I also tried putting a spare HDD on just incase the one i had was faulty but a clicking noise came from that also? i have a 550 watt power supply on it and the card's minimum is 450w. I dont think its an actual HDD problem but my guess its a power problem? which is also confusing because i have the same PSU on my working pc. Any help? thanks in advanced !