I too ran memory tests, hard drive tests, mobo tests, and CPU tests & all of them said everything was fine or so the tests thought!
That was the exact same problem I was having trying to do a clean install of Windows was file corruption!
I had to do this 4 times before it halfassed installed the operating system with all kinds of problems.
Then a few days later when I tried to turn it on it wouldn't even bootup.
Just the lights came on and fans would spin with a Black screen.
So, there's a PC shop near my house (the only one in town) that offers free diagnostics so I took advantage of that and they verified the mobo was bad
by testing out all my components in another mobo. (In hopes that I would buy the $25 "Cheap generic mobo" they had for $140! Yea right! LOL)
So I ordered a new mobo for it and all was once again well.
Unless you have your mobo bench tested to see if in fact it is bad, I wouldn't put all my bets on it...but it sounds like it to me.