I am trying to install Fedora 23 WS and I am running into a problem.
I have tried booting from dvd and usb with a live image. I have created the media with LiLi, Fedora USB creator, and burning the ISO to disk. Every time it boots I get dropped back to a Dracut with a message saying it couldnt find something in /etc/../../
Here is where it gets weird. This same issue happens with Fedora 23, Korora 23 and Fedora 22 ( the Fedora 22 is a disk that I have sucessfuly used in the past so I have no idea why it wont work)
Its the same error every time dropping me to dracut
I have tried UEFI and legacy - no change I have tried adding nomodeset - no change I have checked the hash of the downloads - they check out fine I have DEFINITELY used the Fedora 22 dvd before without a problem.
I have been struggling to get fedora 23 working properly for months on my X99 platform, eventually I went with a 4.4.5 kernel and all the problems have stopped. That being said, this was a hardware specific issue on my part (qq Asus mobo), and it may as well not work for your case.
Maybe letting people here know what hardware you are on and they could be more specific? :)
Z77 should have more than fine support from 4.2 kernel for starters.
About your bios config though, CSM you said you tried both enabled and disabled. How about secure boot? Have you unloaded the keys and disabling it?
On Asus motherboards, sometimes you get conflicts when secure boot is enabled, and you see USB errors that may or may not halt the boot. At least from my experience that is... :(
I would give it a try with just a single drive plugged in. No soundcard, dvd etc. Save your BIOS config (I think you can on that board) and reset back to factory defaults. Then try again.
Failing that doe you get the same errors with other distos with recent kernels e.g. Sabayon?
Did you download from the Fedora website? Check the .iso md5sum, I have Fedora 23 on all my systems, and actually reinstalled it on my Laptop yesterday. No problems here.
That's the same software I used for the install. Works well.
Does your system have intel integrated graphics? Pull/disable the nvidia card and install via intel. Then install the propitiatory Nvidia drivers (i suggest from negativo17) then put your card back in.
Its very possible that if the custom bios is reporting the card differently that its not picking it up and supporting it properly and since the card driver is in early development is just fails.