Setting up raid on Crosshair V formula Z

Hello all.

I have finally built my first PC and it is successfully posting.

I am entering the bios and am curious as to the order in which I need to set up a raid volume, do I do it before installing windows 8 to it or afterwards? (I want to raid to 500GB 850 Evos in raid 0 I know risky)

also I;m having trouble actually setting up the raid volume, Im not sure if theres another error tripping up the system, my LED reader reads "66" and I get the following message

"The current BIOS setting do not fully support the boot device. Press [F1] to enter the BIOS setup.

Go to Advanced > Boot > CSM Paramaters, and adjust the CSM (Compatability Support MOdule) settings to enable the boot device.

I can enter the CSM Parameters but am unsure as to what to set it to.

Any and all advice and help is greatly appreciated. EDIT!!!!! I'm a bit of a dope, I was being waaayy too gentle with the sata power cables, so the Evos werent getting power, hence no detection. I have now successfully made a raid 0 with 999GB! gonna install OS in the morning!