Been trying for days to create a USB Recovery Tool for my Inspiron 15 that has a Preparing Automatic Repair loop which is impossible to resolve. 
Now it seems it is impossible to create this tool. The instructions seem to be incorrect.
This is the page where I was led to after entering my Service Tag on the website:
https://www.dell.com/support/home/uk/en/ukdhs1/drivers/osiso/recoverytool
This is the brief instruction:

How it works:

1. Download and install the Dell OS Recovery Tool.
2. Launch the Dell OS Recovery Tool and enter the Service Tag of the PC that needs its operating system reinstalled.
3. Select the operating system image you'd like to install, and the OS Recovery Tool will build your bootable USB recovery drive.
4. Install the operating system using the newly created USB recovery drive. This will remove all data and software from your PC's hard drive and restore the factory-installed operating system.

The reality is that you get to 'launch' the downloaded recover tool and there is no where you can enter a Service Tag, or operating system image... just a pop up with Install or Extract. 
No where do ANY of the (apparently incorrect) instructions tell you how to make your USB into the recovery tool (i.e copy files over?)

So - HOW do we create the tool??? 

Once it is created I can get to F12 and change the Boot Manager to boot from a USB - but How do I create this bootable USB??