the damn thing no longer POST after windows 8 install

To make a long story short, I tried to dual boot Win 8 on my Win 7 HTPC

I did this from a USB, while it was installing I went to do some other things around the house, then I heard what sound like my PC rebooted. When I came over to see, it had actually shut down. So i tried to power it up, power lights lit but nothing happens. Hit the reset button nothing happen, press and held the power button to hard reboot but it doesn't seem to response to it. My only other option was to flick the power switch on my power supply.

Now whenever I hit the power button, I can hear my drives spin up my DVD rom response to ejeck etc... but no more power lights.

I've sinced pulled every attached component, HDD etc.. off and still won't post. Sounds like a fried motherboard. Before I go buy a new MB just wanna see if there's anything I can do.

the mb/cpu is a a few years old amd 9900 quad power supply is less than a year old.

i think it's about time for a core i7

update:

The problem still exisit...

I bought a new Thermaltake TR2 500w ps, asus P8z68 motherboard and a core i5 2400, Corsair xm3 8gb 1600 ram and corzair force 90gb SSD

Hooked everything up and hit the power button, the exact thing happen. I can see the chasis fan and cpu started to spin then turn off. It would try to spin up two more time and stay quiet.

I disconnected all the front panel connection and use my screwdriver to short out the power button and it would do the same thing.

What else could be bad? The entire PC is basically brand new.

LOL I've been eyeing new components anyways, the PC dying basically gave me a push to pull the trigger.

I don't think the case has anything to do with it. Since I pulled all the components out of the case and did a bench test on a table with nothing connected beside. CPU, 1 ram and MB to the power supply and still no luck.

Did the same thing on the old MB/CPU combo and this time the old stuff stayed on but I couldn't get video from either onboard or pcie. I hooked up the speakers to see if I can hear anything POST beep error but didn't hear anything either. I'm about to head back to the store and buy another MB to see if that was my problem

I went out and got an MSI p67a-gd65 at fry's and got everything up and running with Win 8 but I'm hating it right now so Win 7 is coming back in after I write this.

Further inspection, i discovered that I possibly have a bent CPU socket pin. Oh well,

Can you imagine using your smart phone on a big 55" screen? if it was touch screen it'll be a different story but man. I think it's also because I'm not familiar with the interface yet. It'll take some time for sure.

It isn't like coming from Vista to 7 where most common things are familiar. Crap I had a hard time finding the shutdown button. I just finished putting 7 ultimate and configured my 7MC 90% to where it should be.

SSD is the way to go. It's pretty fast the way it is but I think I'm going to go back and exchange the core i5 2400 for i7 2600 tomorrow.