grub2 - Are all three grub entries after running Boot-Repair needed?

After running Boot-Repair to fix things when dual booting windows 8 and Ubuntu 12.04.3, multiple entries are left in the grub menu. Three come from

menuentry "Windows UEFI bkpbootmgfw.efi" {
search --fs-uuid --no-floppy --set=root 4659-4959

chainloader (${root})/EFI/Microsoft/Boot/bkpbootmgfw.efi
}

menuentry "Windows Boot UEFI loader" --users "" {
search --fs-uuid --no-floppy --set=root 4659-4959
chainloader (${root})/EFI/Boot/bkpbootx64.efi
}

menuentry "EFI/Lenovo/Boot/bootmgfw.efi" {
search --fs-uuid --no-floppy --set=root 4659-4959

chainloader (${root})/EFI/Lenovo/Boot/bootmgfw.efi
}

The second is recommended in the Boot-Repair documentation as the one to use
to boot Windows 8, but equally it seems the first option does the job fine too, and the last give access to settings. Do I really need all these, or can I simply comment them out in 25_custom?

Similarly, given that the original boot entry for windows in 30_os-prober is defunct, can I just comment it out?

What is the difference between each of these efi boot loaders anyway?