I've never seen that happen, but I'm not using Windows 8. I noticed that the 2.60 UEFI/BIOS for your board is very new, dated 1/23. Did this problem happen before you installed 2.60?
On a side note, I see that the 2.60 BIOS/UEFI notes say: 1. Update RAID ROM. 2. Support Intel UEFI RAID configuration in BIOS setup. I want this for the Z77 Ex 4 board!!!