See the Google search below which provides quite a few links with answers to your question.
Google Search for "change computer owner name"
Hope this helps.
I gave my computer to my neighbor that I trust. But he sometimes is visited by a relative who uses his computer. I was not worried about the computer having my name as the owner but should I be concerned about who uses his computer? Is there a way I can change the name of the owner? I would not like anyone to visit a site and have my name associated with it.What should I do?