@Holgi, Thanks for your quick reply, I will try that, nothing to be lost!
If it doesn't work, Windows 10 will be OK, but would really like to try Windows 11.

I am playing with "Ventoy" mainly for using Linux Distro's but wanted to try installing Windows 11 on a Toshiba satellite Laptop.
This laptop was given to me running Windows 10 Pro and I created my own MS Account for it.
All was OK until the HDD died.
When replaced , I asked MS for the Product Key ...