If you ever created a bootable disc, you should be happy to forget about that! Yes, no more primary partitions, MBR, bootsectors and all that crap. Now you just copy the needed files, and this is called EFI / UEFI, don’t mix with Fifa and UEFA.
For instance, you need a bootable Windows 7 installation. No problem! Take any drive which is formatted into FAT32. I have a USB HDD, a part of which is FAT32 formatted for use in devices that don’t read NTFS, and the rest is NTFS formatted. If I make it a bootable installation media with the old, MBR scheme, I would have to delete the second partition and loose all data.
When using UEFI mode, I just unpack the ISO containing Windows 7 x64 installation to the root of the FAT32 drive. Then you open the Efi folder, go to Microsoft subfolder and copy the Boot folder from there one step up, that is to Efi/Boot. Now you will also need bootmgfw.efi. The easiest way to obtain this file is to copy from a working Windows 7 x64 installation. Or download it. Copy it to the Boot folder and rename to bootx64.efi. You’re done. It’s worth mentioning that all this is worth doing for Windows 7 x64 installation only. 32 bit versions don’t work, and the new Windows 8 installation media already has the necessary files in right places.
Reboot your computer and press the button to enter BIOS boot menu. Different manufacturers may have it different, but in most cases you will see the same drive as two separate lines – one MBR and one UEFI. Select the UEFI one. Windows installation will start, and to boot it we basically just copied over the files, without creating bootable partitions and all that stuff. Another good thing is that if the drive you’re installing Windows to doesn’t have a filesystem, the installation will create three partitions which form GPT filesystem. It is a step over the old MBR filesystem, and Google will be happy to tell you why is that so exactly.