NEW! The ReleaseToManufacturing (full release) version is here but it is the Developer version and is limited to 90 days only. If you have an MSDN subscription then get the full RTM version(s) from here. The 32-bit (x86) version is recommended if you are installing Win8ToGo on a USB Media Flash drive as it will run on both 64-bit and 32-bit systems

I also successfully booted Win8.1 9600.16384.WINBLUE_RTM.130821-1623_X86FRE_ENTERPRISE_EVAL_EN-US-IRM_CENA_X86FREE_EN-US_DV5.ISO Enterprise 90-day eval version using these instructions (on a Fixed-disk type of USB drive).

BCDBOOT U:\Windows /s U: /f ALL /v

Note: If this fails to recognise the /f ALL switch, use the Win8 version of bcdboot that is on the USB drive - U:\Windows\System32\bcdboot.exe, e.g.

U:\Windows\System\BCDBOOT U:\Windows /s U: /f ALL /v

8. Use the Safely Remove Device System Tray icon to Eject the USB drive

Putting Windows 8 to Go! onto a USB 2.0 16GB Lexar Jumpdrive using

a Windows 7 system (install.wim was from a 32-bit version 2.8GB Developer Preview)

Note that I had copied the install.wim to a folder on my C: drive first.

Preparing a USB HDD drive (H:) from a mounted ISO on N:

Now go boot it on something!

It may reboot several times during kernel and driver detection, so remember to make it boot from the USB drive each time (it may quickly reboot back to your internal HDD the first time!).

It is preferable to install the correct Windows 8 bootmgr by re-running bcdboot.exe - see the next section below for details.

"Windows could not complete the installation. To install Windows on this computer, restart the installation."
If you see this error message: The USB drive must have an Active (bootable) partition. Use RMPrepUSB to prepare the USB drive or use DISKPART to make the partition is bootable. To check, use RMPrepUSB - Drive Info and check it is listed as 'ACTIVE'.

PRODUCT KEYS

The Release Preview 2012 version Product key is TK8TP-9JN6P-7X7WW-RFFTV-B7QPF,

Skip the Product Key entry if asked on the 2011 early Developer Preview version or use 6RH4V-HNTWC-JQKG8-RFR3R-36498.

The Beta Consumer Preview 2012 version needs to have a Product Key entered and this cannot be skipped - the Beta trial key is DNJXJ-7XBW8-2378T-X22TX-BKG7J.

Always shutdown Windows before booting the USB drive on a different computer (you do not need to run sysprep).

The USB drive will reboot much faster once the 'Metro' desktop has been reached and all the driver detection has taken place on the first boot on a new system.

If you enable Hibernate, do not Hibernate Windows and then try to boot it on a different computer or it will crash!

If the Metro Apps don't seem to run, try changing the screen resolution to a larger size - Metro apps only run at a screen resolution of 1024x768 or larger! If Internet Explorer won't run from a Metro icon due to a low screen resolution, run IE from the Windows Desktop IE shortcut instead.

Slightly improve the boot speed

Once you have the USB drive successfully booting to Windows 8, you can change the bootloader (bootmgr) to the Windows 8 version as follows. This allows it to boot slightly faster (by about a second or two).

1. Boot from the USB drive to Windows 8 as usual

2. Use Windows Explorer to find the C:\Windows\System32\CMD.exe file and right-click on the file and choose Run As Administrator

3. Type the following command in the shell console window:

bcdboot C:\windows /s C: /f ALL

UEFI Booting

The USB drive must be of the 'Fixed disk' type (not Removable type).

You can make a WinToGo USB hard drive boot to both UEFI and MBR by creating a FAT32+NTFS partitioned drive.

See http://technet.microsoft.com/it-it/library/jj592685.aspx#stg_firmware - Roaming between different firmware types. (thanks to DevaDev for the tip).

Extract the wim file to the NTFS partition, then run the BCDBOOT command.

T: U:

Use the U:\Windows\system32\BCDBOOT U:\Windows /s T: /f ALL /v command.

To add this to an Easy2Boot USB multiboot drive - see here.

For UEFI-only booting

If you want to enable UEFI booting as well as MBR booting, you will need to reformat the USB disk with a GPT partition structure and use the 64-bit version of Windows 8 as the ISO source.

The USB drive must be of the 'Fixed disk' type (not Removable type).

Instead of using RMPrepUSB to format the USB drive, use Windows Vista/7/8 Diskpart.exe. You will need to create a 100MB EFI System partition, a 128MB MSR partition and then the basic data partition(s) according to the size of your USB drive. You must add the partition types using the correct GUID identifier in the diskpart script.

The EFI partition and basic data partition(s) will need drive letters.

Use the command:

diskpart /s diskpart.txt

and use notepad to make a diskpart.txt script similar to the one below (change the disk number and volume size, which is in MB, as required):

rem === create GPT disk with two partitions, system and data ===

select disk 1

clean

convert GPT

create partition EFI size=100 offset=1024

format quick fs=fat32 label=EFI

assign letter=S

set id="C12A7328-F81F-11D2-BA4B-00A0C93EC93B"

create partition MSR size=128

create partition primary size=80000

format quick fs=ntfs label=System

assign letter=U

set id="EBD0A0A2-B9E5-4433-87C0-68B6B72699C7"

create partition primary

format quick fs=ntfs label=Data

assign letter=V

set id="EBD0A0A2-B9E5-4433-87C0-68B6B72699C7"

exit