Thank you mrgeek for your reply. I did find the method I had used to do this years ago on Window 7.
I have now corrected the account name and solved my problem.

1:- Created a new admin account....

Sadly I need to rename my Win 10 user account as a character used in it clashes with a software program. The problem is new to this product version as I have used earlier versions since 2012.
How...