The format used to define the hard disk partitions in computers with UEFI startup firmware. The GUID Partition Table (GPT) replaces the previous master boot record (MBR). GPT partitions can hold 18 ...

Some users have reported that the installation process is interrupted when they try to install Windows OS on their hard disk. As soon as they press the Install now button in the Windows Setup process, ...

I've neve used them personally but I know parted can create them and it looks like the kernel option is CONFIG_EFI_PARTITION which is on by default in Debian, I don't have an Ubuntu machine to check ...

Hmm. So you're using the Partition tab in Disk Utility, and you're selecting GPT in the Options dialog, and you set one partition to be FAT and the other to be HFS+ (so that neither is unformatted ...