I read your post from Tom's hardware and you said sometimes it took a long time to get thru the BIOS post. When you first turn your PC on, it's going thru the post process trying to identify what hardware you have in your system. I had this problem in the past that it took a long time going thru post, it turned out that one of my hard disk was corrupted so I would think something is not right,
now we have to isolate which one causing it.
So, first you do what the guy told you, configure your system to bare minimum, ie. 1 dvd, 1 hd, memory, keyboard and mouse.
But before you do this, take out the memory and clean the contact real good and when putting back in, jiggle a little bit to make sure they make good contact, I also would replace the Sata cables for the DVD and the HD to eliminate the cause of a bad cable, sometimes we over look the little things like that.
If all is good, try to install Windows 8, right after you click "INSTALL NOW", then click on Custom Install, in the next screen, click on "Drive Option(Advanced)", hi-light each partition then Click "Delete", Next you want to create a New Partition, Click on "New", Windows installation will tell you it will create a 350MB reserved partition also then click Next to install.
After the installation and if the problem still persist, then the next thing I would do is get a copy of Memetest86+, it is a DOS version of memtest, you have to burn it to a cd then boot to run it to check out if your memory has any bad spots on it. Trust me, if your memory stick has any bad spot, it will cause Windows a lot of problems because you know before running any programs, The system must first load that program into RAM before running it and if it happens to run your system program then it will crash.
There is nothing magic about computer, and believe me if you take your PC to the shop, this is what they would do.
Well, good luck with your trouble shooting