Windows 10 installation keeps restarting to language & keyboard choice

We had a customer that was trying to install Windows 10 on their HP laptop.
After the installation had copied the files to the hard disk drive from the USB key, the laptop restarted; only to return to the same point of the installation where you choose the language and keyboard choices.
The installation would not advance past this point.
Normally the Windows 10 installation will restart and carry on with the installation even if installation USB key is plugged in.
The laptop was set to boot from the USB stick in the BIOS and would keep booting from the stick after the restart.
What I did was tell the customer to remove the USB stick when the computer says that it is restarting.
When they did this the installation carried on as normal!