I have GA-Z77X-UD3H (rev. 1.1) I updated from F20d to F20e and now the bios will not detect P0 (Where my Windows7 OS is located). It will only detect P1 (Windows 8 Drive). Since F20d is no longer available on the Gigabyte site, I had to downgrade to F19e and everything is working again. I have 2 SSD's installed (1 for Windows7 (P0) and 1 for Windows8 (UEFI P1)) and will set the bios to boot to which ever system that I am using, but again, once I updated to F20e, the bios will not show P0 as an available boot option.