USB 3 Issue with EUFI installation

[danskeman]

Hi,

I have successfully installed Windows 10 Technical preview (64 bit) on a 100 GB external hard disk (GPT formatted etc), for booting on a 64bit Sony Vaio with EUFI booting.

I have set my eufi/bios to boot fom USB,and the hard disk boots perfectly when plugged into a USB2 port, but fails when using a USB3 port.
As the pc boots up, it ignores (or faisl to detect) the hard drive properly and then just boots up into normal windows in the pCs internal hard disk.

However, if I try and boot from a USB3 boot pendrive for another program (Macrium Reflect), the PC boots up fine, so I know the USB3 port is fine, and the PC can boot from it.

I suspect that the USB3 drivers are not being properly installed by wintousb, or being picked up from windows 10.

Any ideas/suggestions?

[SteveSi]

Windows 8/10 contain native USB 3.0 drivers. I don't think WinToUSB adds any. Try Win8. If both fail then maybe your hardware is not supported (did you have to install special USB 3 driver when installing Windows onto internal HDD?). if only Win 10 fails, then maybe MS have not added in all USB 3 drivers yet?