Ok so just to thresh out what Im seeing, and hopefully others will correct any errors below.
1. UEFI has 'secure boot'* - which on machines shipped with Windows 8 has 'keys' embedded in it that prevent any 'non-signed' device from being bootable on the system. The device, in order to boot, needs to have a secure signature. Apparently there's no such thing as a boot disk thats not made by MS that fits this 'signature' criterion?.
Note that 'secure boot' is NOT a microsoft invention, but MS-keyed systems are probably the most widely implemented.
*A really short, sharp, informative summary of 'secure boot'
HERE for anyone interested
2. So, if you want to boot from a 'non signed' device, you have to go to the BIOS and switch off secure boot.
The process and language for doing this varies between manufacturers.
Acer:
AUTHENTICATION - SECURE BOOT - DISABLED
BOOT OPTIONS - LAUNCH CSM - ALWAYS
Source:
www.eightforums.com/tutorials/17058-secure-boot-enable-disable-uefi.html
-
Asrock:
SECURITY - SECURE BOOT - DISABLE
- note - to re-Enable - select "Install default Secure Boot keys" - YES
Source:
www.eightforums.com/tutorials/17058-secure-boot-enable-disable-uefi.html
-
Asus:
UEFI SETTINGS - BOOT - SECURE BOOT - OS TYPE - OTHER OS
-
HP
- NOTEBOOKS
SYSTEM CONFIGURATION - BOOT OPTIONS - SECURE BOOT - DISABLED
- DESKTOPS
SECURITY - SECURE BOOT CONFIGURATION - SECURE BOOT - DISABLE
LEGACY SUPPORT - ENABLE
source:
http://h10025.www1.hp.com/ewfrf/wc/document?cc=uk&lc=en&dlc=en&docname=c03653226
-
MSI
ADVANCED - WINDOWS 8 CONFIGURATION - SECURE BOOT - STANDARD
source:
http://65.244.195.67/support/formviewer.asp?esoformid=3058
-
Toshiba
SECURITY - SECURE BOOT - DISABLED
ADVANCED - SYSTEM CONFIGURATION - BOOT MODE - CFM BOOT
source:
https://aps2.toshiba-tro.de/kb0/TSB2B03F30002R01.htm
-
Sony
SECURITY - SECURE BOOT - DISABLED
Source: docs.esupport.sony.com/pc/SVT1112_1312_1411_series/EN/contents/07/02/08/08.html?search=secure
-
Not an exhaustive list, but indicates how much time wastage can occur for anyone not familiar with the particular nuances of the system being worked on. ("CSM mode" setting, for example, has tripped me up in the past with Legacy enabled and still not able to boot to anything). Hopefully something there will save someone else some time.
-
By default, Windows 7 installers do not support secure boot. FWIU Secure boot prevents Windows 7 from being installed using a standard DVD. That means that if it is enabled on a dual boot machine, it can prevent windows 7 from booting. Conversely, if disabled on a machine that came pre-installed with Windows 8, Windows 8 will not boot.
A solution to the Windows 7 install issue is to make a UEFI bootable Windows 7 Flash drive (So that its not necessary to disable Secure boot to install Windows 7)
INSTRUCTIONS
A caveat for us techs working on a W8 machine with a boot disk is that we have to go back and re-enable secure boot to get back into the machine's OS
-
Secure boot can break the OS when new hardware is installed
"Windows may no longer boot after the changes are made. You may encounter behaviors such as hanging at a black screen, Windows crashing with a blue screen, or BIOS error messages to change your settings"
source:
http://support.microsoft.com/kb/2800988
-