[Boss1996]

I've just built a new PC and it turned on perfectly when I first tried it, I then moved onto installing windows and got to the 'Expanding Windows Files' bit, was a bit slower than a remember but was doing it fine anyway, but then the computer just turned off and if you try to press the power button, nothing happens. I have a Ethernet cable plugged in and the lights show that is has power. Also there is a green light on the motherboard suggesting to me that it is fine. I am a bit stumped at this, I've built many computers and then have all worked fine and I have never come across a problem like this before. Any ideas guys?

Just a quick rundown of the specs just in case:
Intel Core i5 3470
ASUS P8Z77-M
Nvidia GeForce GTX 650Ti
Corsair XMS3 RAM 8GB (2x4GB) @ 1600MHz (showed up as 1333MHz in BIOS)
Seagate Barracuda 1TB HDD
Zalman Z9 Case
XFX Pro Series Core Edition 450W PSU

Thanks,
Boss1996

Original questions I asked on Yahoo Answers!: http://uk.answers.yahoo.com/question/index?qid=20130221031525AATJ9Bu

 

[cgull]

try this:

take out the ram and then install 1 stick only..if still no go swap sticks then try 1 stick of totally different ram if you have any..also reseat all power connectors,.

when you turn it on do any fans spin? especially cpu

try different psu if you have one

 

[frogger4]

Yeah, start off with the very basics. Unplug everything except what is necessary (as in, use onboard video, unplug hard drives, etc) - then see if you can boot into the BIOS. What the person above said about RAM, that could help. If none of this gets you to the BIOS screen, power off, unplug for a minute, and clear the CMOS (either pull out the mobo battery, use the jumper, or the clrmos button if you have one).

Hopefully this will get you started!