[sirace1]

I did a quick google search on change windows xp registration name and this was the information that came up.

I hope it is what you are looking for......

Change the Registered Organization/Owner of Windows XP
This tweak allows modification of the registered owner and organization of the Windows XP software.

Note: This tweak has nothing to do with Windows Product Activation (WPA) and will not allow you to register illegal XP software.

[Start] [Run] [Regedit]
Registry Key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion
Modify/Create the Value Data Type(s) and Value Name(s) as detailed below.
Data Type: String Value // Value Name: RegisteredOrganization
Data Type: String Value // Value Name: RegisteredOwner
Setting for Value Data: [Modify the Values to Reflect Current Information]
Exit Registry and Reboot