Win 7 Install on USB Stick not booting

[Guest]

I am working on a Toshiba Satellite P850 which came with Win 8 now upgraded to Win 8.1 (64-bit) which is still installed.
I now want to install Win 7 (64-bit) so downloaded the iso (X17-59186) and using Rufus 1.4.12.535 burnt this to a usb stick using the boot setting MBR partition scheme for UEFI computer.
In the BIOS settings of the Satellite, boot mode is set to UEFI and the boot order has USB at the top.
But, the USB stick will not boot - the current Win 8.1 boots instead.
Any ideas on what the problem might be?

 

[Tiago Sa]

Is the usb plugged in properly? And on rufus did u burn it to be a bootable device? thats what i did and it works fine

 

[Guest]

USB stick is plugged in OK - it is detected in the BIOS

 

[Tiago Sa]

On rufus did you burn it to be a bootable device?

 

[Guest]

On rufus did you burn it to be a bootable device?

Yes, Rufus was set to burn to bootable device

 

[Guest]

Update - I have tried a different USB stick and different burning software (ISO to USB) - same result - no boot.

I'm thinking that I need to change something in the BIOS or the ISO file is corrupt.

 

[Guest]

All sorted. I had to change the boot mode to CSM in the BIOS. Will have to change it back to UEFI to boot Windows after the install.

 

[Tiago Sa]

Great!