Posted by: Ed Tittel
After posting about Windows 8 UEFI Install on December 19, 2012, I’ve now been through that exercise enough times to have learned some “don’ts” along with the instructions I provide in that blog, and those you also find in the EightForums tutorials on creating a bootable UFD for UEFI and doing a Windows 8 UEFI install. As always, I keep reading about more and better ways to do things in setting up the UFD and performing the install, and I found some approaches to avoid as well as some potential gotchas to explain. Here goes:
1. Despite what other sources may say, you can’t use the Microsoft Store’s Windows 7 USB/DVD download tool to build a bootable UFD that works with UEFI. It will cheerfully deploy the Windows 8 ISO on the UFD, but when you examine the drive inside your PC BIOS for boot targeting, it lacks the essential UEFI: label needed to drive a UEFI drive layout during Windows 8 installation. That said, this tool is good for one thing: It checks .iso file integrity to make sure they can and will install properly.
2. It’s a grand idea to check the integrity of the Windows 8 .iso file you set up with diskpart and whose contents you copy to your bootable UEFI UFD. I didn’t do this on my first try, and sure enough my ISO file was corrupted. It threw a “missing media driver” error in the initial stages of the install, and only Internet research showed me that this normally indicates integrity problems with the files extracted from the ISO for use on the UFD. A quick download from MSDN and a rebuild of my UFD and everything on the next attempt worked exactly as it should.
3. Disconnect all other Windows boot drives from your target system before you attempt a UEFI install. I didn’t do this on my second attempt, and learned that the new drive simply uses the EFI partition on the original system drive to do its boot thing and doesn’t create a native EFI disk partition structure on the second drive (because it’s already got a working one on the original EFI system drive, thank you very much). Unfortunately, this did some very weird stuff to the EFI and boot partitions on that original system drive, too. In fact, when I booted into that original partition, the OS wouldn’t come up. I had to reboot from the UEFI UFD, run the repair option from the installer, and restore my most recent system image (taken earlier that afternoon before all these shenanigans began, as a necessary precaution) before I could restore the system to normal, proper operation. Subsequent research showed that some installers actually disconnected ALL other drives from their systems besides the intended system target drive when doing a UEFI install, because of other odd issues here and there that popped up when other drives were present.
4. I learned that the Windows boot manager will let you boot directly into a VM without also booting the underlying host machine. I didn’t realize what was going on at first, and was nonplussed at the presence of a virtual Ethernet interface that couldn’t connect to the Internet (of course not, without the virtual switch connection to the host, there is no Internet link). But this sorted itself out pretty quickly, and I learned to include VM in the computer name for all Windows 8 VMs going forward so I can tell what’s what when the boot manager asks me which OS I should boot!
Here’s what Disk Management reports as the layout for my EFI drive:
My next goal is to create a bootable UFD or DVD that will let me run the UEFI shell from a cold boot. So far, I’ve been unable to get that working on my UEFI systems, either. I hope to make some informative and useful reports on the shell environment in the relatively near future. Stay tuned!