I have an official Windows 8 developer x64 preview ISO from 2011.09, that was released by Microsoft, containing a sources/install.wim that is about 4.4 GB in size. I think this was a preview image that also contained the development tools.
Thankfully, none of the actual release Windows 8 ISOs I have seen (so far) seem to contain a > 4 GB file. Probably this is because someone at Microsoft realized that the EFI committee's questionable decision to pick FAT32 as their bootable filesystem means that we're going to be stuck with 4 GB limitations with UEFI boot in the foreseeable future, and thus > 4GB should be avoided.
It was actually quite funny to see Microsoft release a supposedly UEFI-enabled version of Windows 8 preview... that couldn't be installed in UEFI mode...
By the way, I am the author of Rufus, so I guess the first thing I should really say here is a massive THANKS! for promoting the application for the installation of Windows in UEFI mode . I hope most people will find it friendly enough to use for this task.
Sadly, there's nothing I can do with regards to UEFI images with a >4GB file, as it really boils down to a FAT32 limitation. Unless I'm mistaken, UEFI boot mandates a FAT32 partition for boot, and FAT32 cannot accommodate files larger than 4 GB.
Still, if there's any feature you'd like to see added, with regards to UEFI or something else, or if you think you encountered a bug, don't hesitate to post here.
Oh, and for those interested, I have just released a beta version of the upcoming Rufus v1.3.3 here.
It shouldn't change much in terms of UEFI installation, but if you feel like testing the new version, please go ahead.
I do not remember having problems using the Windows 8 developer x64 preview ISO, on a USB Pen Drive formatted to FAT32, but it is some time ago.Originally Posted by Akeo
If I remember correctly, 2 developer x64 preview ISOs were made available by Microsoft: the standard one (which I guess didn't have a >4GB file) and one with additional developer tools, which was called "Windows 8 Developer Preview with developer tools English". If you picked the latter, this is what you ended up with:
The only thing I think I did was rename the ISO to make it more MSDN like, but everything else is untouched.
As a matter of fact, since having a >4 GB file is a good way to identify software limitations, not only with UEFI but with other software, I can point to an official post of mine on the libcdio mailing list (libcdio is the library used by Rufus for ISO support) with the original public link to the ISO:
Now, with the preview over, that link is pretty much dead. But I hope it'll be enough to confirm that Microsoft did indeed provide an ISO image once, with UEFI support, but that was impossible to install from USB, in UEFI mode...
You have it correct for the two versions of Develop Preview ISO files. The one with the added developer tools pushed it over the 4 GB barrier.
Thank you for creating Rufus.
Microsoft have overcome the limitations of FAT32 by broking up the Install.wim, in to files under 2.5gb.
OEM UEFI Pre-installed Windows 8, Recovery Partition.
OEM version of the Recovery USB.
using the OEM version of
Recovery Drive - Create with USB Flash Drive in Windows 8
WarningDeleting the Recovery Partition is NOT RECOMMENDED
Still it's kind of sad that something like UEFI, that was also designed with 64 bit support in mind, has to work around 32 bit limitations. Then again, if the choice was between exFAT and FAT32, I can't entirely blame UEFI for going with the much more open FAT32...
Do remember that UEFI is about 20 years old.
Unified Extensible Firmware Interface - Wikipedia, the free encyclopedia
The original motivation for EFI came during early development of the first Intel–HP Itanium systems in the mid-1990s
thanks you!! It's useful for me. before that I usually edit my ISO file and create usb boot by HPusbdisk with DOS system. Now, rufus do it very well!!