WinToUSB with Win7 64-bit will not boot on UEFI PC

[Galco]

Hi!
With no problem I created a live Windows 7 on a Kingston Ultimate 3.0 G3 USB drive. The system runs perfect on my older laptop with Windows 7.

However I cannot boot from a newer Win8.1 system. The USB drive is not listed as bootable. I already disabled "secure boot".

Do I need to create an additional EFI partition (FAT32)?
(BTW: DiskPart shows the USB drive not labeled GPT.)


Thanks!

Cheers,
Galco