Okay it seems like it is a generally accepted idea that windows 8 will boot in UEFI mode natively in all INTEL Macs, but I have to say otherwise because I personally encountered this strange problem and does not know how to proceed. Here's my story and please help if you have the same machine/problem. I have two iMacs at home, one is iMac7,1 (mid 2007 iMac), and the new one is iMac 12,2 (2011 iMac). So Windows 8 is now approaching and I was trying to install it to both iMacs. Since the 2011 iMac is my work station now I try to experience the system on my old machine, the 2007 Mac. So I formatted one of my USB drive as GUID, and get a FAT32 partition, and placed the WIN8 ISO content on it. It is a working USB drive because it boots nicely into the installer in iMac12,2, however, it simply hangs in iMac7,1, at /eft/boot/bootx64.efi, keep the computer on for half an hour nothing changes. Whether I call it with the native bootloader in Mac (the one you pressed and hold Alt), or rEFIT won't change a thing, it just hangs in the same place with same message. I also tried recording a DVD from ISO image, and format the internal hdd as GUID (wipe bootcamp), and place the DVD content in the internal hdd to boot, but stuck in the same place. I know it is something special about this particular model of iMac that stops windows 8 from booting into UEFI mode, but I had no idea what that "specialty" is, and I hope you guys can enlighten me with some better ideas. The other purpose of this thread is to bring about one additional thing to the forum so that other people can benefit from this (I think), that not all Macs are the same when it comes to issues like this. It is somehow hardware related, and specific to each model. For example, most (if not all) intel Mac guys probably know about this fact that intel Macs cannot boot off MBR bootable drives from a external USB source, it can only boot from a CD. Installing windows on ordinary PC almost never requires burning any CD/DVD any more by using USB drives, but for Macs, we usually still have to rely on DVD (not sure if it is intentionally done by Apple to make windows look really dumb and outdated). However, there are cases where people report that USB MBR bootable drive works just for them, it is rare but I've definitely seen this guy saying that it works like charm for him in his Macbook or Macbook pro (sorry I forgot the name but I'm sure some of you have heard of the same story). That and my story here shows that no two Mac models are the same, what works for 1 probably won't work for the other, so I suggest that when we say we had a success on something (especially windows related issues), we'd better also explain the setup we have, so other people can benefit from it. For me I'm sharing this information hoping that I can get a solution from you guys, if not at least people who own the same machine and/or with the same problem can save sometime trying. BTW it's probably something related to the firmware of the iMacs, but for 2007 iMac there's no more updates coming so it will probably never be solved unless we can get pass this.