How do you change your network name?

Okay, so I got a laptop from an oldl friend of mine and i've changed the names on EVERYTHING but when it locks and it makes you sign in. I could change my password but not my name. Like when I shut my laptop and it hibernates and you open it back up it says this computer is locked please log in to proceed. There is a name on there and i want it to be mine. I'm so confused!! Someone please help.How do you change your network name?
1. Click Start, and then click Run. In the Open box, type regedit, and then click OK.



2. Locate the following registry key:



3. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Wi?NT\CurrentVersion



4. Backup the registry by exporting the key. See ';Backing up the registry'; for more information.



5. To change the company name, do the following:



In the right pane, double-click RegisteredOrganization. Under Value data, type the name that you want, and then click OK. To change the name of the registered owner, do the following:



In the right pane, double-click RegisteredOwner. Under Value data, type the name that you want, and then click OK. Click Exit on the File menu to quit Registry Editor.



6. Close Registry Editor and restart Windows