Problem installing clean Win 10 Pro on Dell Venue 11 Pro 7140

Hi everyone! 

I'm having a problem trying to clean install Windows 10 Pro 64bit on my Venue 11 Pro 7140 tablet.  The reason I'm trying to install a fresh copy is that it won't boot. I get "No bootable devices found" message with 3 options to retry boot, setup utility or to run diagnosis.

So I have grabbed my bootable USB stick with Windows 10 Pro on it and when stick is inserted I get as far as to where you see your drives and can choose where to install it. I can only see some random drive which is 0MB in size so can not format it or resize it etc... 

If I open system info when USB is inserted my Primary Hard Drive is showing as "none" when I take the usb stick out reboot it and run system info it shows 128GB HDD.

How do I make 128GB HDD visible during installation process? 

I have run out of options and any help will be much appreciated.