Have the same problem.
I did steps 1-4 and now it goes straight to an intel rapid memory storage page. I can press ctrl+i to enter a menu in which I'm offered the options of deleting RAID volume or resetting disks to non-RAID. If I don't press ctrl+i it carries on to a black screen with red dots at the top. On the RAID page it says that an 'error occurred' on the first of the two Sandisks.
I'm arranging for Asus to repair it, unless anyone knows what I should do now?
provman :
I have an Asus Notebook X501A and it has just happened to me; I am running Windows 8.1 and I have done nothing at all that may have caused this.
Here's what I did that was succesful:
1/ Select the Boot menu in the Aptio setup utility, select 'Launch CSM' and change to enable
2/ Select the Security menu n the Aptio setup utility, select 'secure Boot Control' and change to disable
3/ Select Save & Exit and press 'yes'
4/ Hold down the power button until the unit switches power off completely
5/ Switch back on and continually press the F9 button for about ten seconds; this should now allow the unit to boot up into the Windows Recovery menu
6/ Select 'Advanced Start Up' and wait until the recovery menu appears
7/ Select ' Advanced Options'
8/ Select 'System Restore' and select a date prior to when the problem occured
System Restore worked perfectly for me; good luck