Quick background, did a custom build (using tonymac recommended components) over 4 years ago, and originally had a triple boot set-up using these instructions:
http://bigfloppydonkeydisk.blogspot.co.uk/2010/07/triple-boot-windows-7-mac-os-x-snow.html - with all working fine having used Unibeast/Multibeast, and Chameleon bootloader ever since (I ditched uBuntu after a year, never used it, but kept the same boot method).
In addition, motherboard is Gigabyte GA-Z68XP-UD3, and the now...
Bootable USB no-longer bootable following Windows 10 upgrade on Dual Boot
http://bigfloppydonkeydisk.blogspot.co.uk/2010/07/triple-boot-windows-7-mac-os-x-snow.html - with all working fine having used Unibeast/Multibeast, and Chameleon bootloader ever since (I ditched uBuntu after a year, never used it, but kept the same boot method).
In addition, motherboard is Gigabyte GA-Z68XP-UD3, and the now...
Bootable USB no-longer bootable following Windows 10 upgrade on Dual Boot