how to change computer owner name

[Bram]

windows vista, home premium, sp2
I bought this computer several years ago at a local department store. It must have been previously purchased ad returned because when setting it up, I discovered the previous owner's name. I haven't been bothered by that since it was for my grandchildren's use, but now that I have taken it over, I can't take it any longer!!! The owner/user account name is therefore, incorrect....but since I have been using it, all my settings are under that user name. Is there a way to "EDIT" a user name? If I delete that user account, what happens to all of my customizations, files and folders?
Signed:
Perturbed and Annoyed

[renegade600]

see the following. it works with any brand, not just hp

https://support.hp.com/us-en/document/bph05548