I once had someone give me their “old” computer, and it had Vista on it. I changed the computer name and the system name to mine, but the name of the person who owned the computer before I did (the registered owner) kept popping up (in addition to mine). I figured it would be easy to change, but it wasn’t. And I couldn’t find out how to change the registered owner’s name to my own.
Well, I found out how to do it, and now I’m going to tell you how! Here you go:
Note: To change the registered owner’s name, we are going to edit the registry. As always, please make sure that you back up  your registry before continuing.
To get to the registry editor, go to your Start button and left-click on it. Then go to the right side and left-click on Run. If your computer doesn’t have a Run button located here and you’d like to add one, click here  for instructions. Another way to access the Run line, is to hold the Windows key and hit the R key (Win+R). In the Run line, type regedit
You are now looking at your registry editor. Navigate  to the following key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\Current Version
When you have gotten to the Current Version part of the key, leave it highlighted.
When you are looking at the registry editor, you can see that the left pane is where we were navigating. In the right pane you can see RegisteredOrganization and RegisteredOwner.
Since you want to change the name of the Registered Owner, right-click on RegisteredOwner in the right pane. A box will pop up. Left-click on Modify.
A new box will pop up. Type the name of the new Registered Owner in the box where the old name was. Left-click on OK.
Now when you look at the right pane, the new registered owner is listed.
And that’s all there is to it!
~ Lori Cline