Windows 8 or 8.1 is unable to boot from a GPT drive on UEFI-enabled devices?

if you formatted or converted your system drive from MBR partitioning to GPT, you must ensure the EFI boot options state "UEFI only". Windows 8 and 8.1 require UEFI for GPT drives, this is a must and there is no workaround.
In old BIOS mode, Windows 8/8.1 will not detect your GPT hard drives or partitions correctly. No booting, no Refresh Your PC or Reset Your PC until "UEFI only" is set. Credits go to Sol for confirming this issue.
You can easily verify whether UEFI works correctly by opening Troubleshoot and Advanced Options in Windows 8/8.1 Advanced Startup screen. If "UEFI only" is set, you'll see the UEFI Firmware Settings option listed. Thanks Sol for providing the screenshot:

"The drive where Windows is installed is locked. Unlock the drive and try again" errors while refreshing or resetting Windows 8 or 8.1 installation. In some cases, Windows forgets the proper drive/partition order and tries to load files from a wrong one. Again, power off your computer and remove power cord. Then disconnect cables from all hard drives except the one where Windows 8 or 8.1 resides, connect power cord and see if boot process completes properly now.
Or, if Windows still works somewhat, try upgrading storage drivers and software using Intel's Driver Update Utility (Internet Explorer installs ActiveX control, other browsers require Java) or find the driver software from AMD's site. This often solves all problems.