From the TechRepublic Windows XP Tips newsletter.

When you install Windows XP, the installation procedure prompts you to enter your user name and a company name. Then, this information displays on the General tab of the System Properties dialog box under the Registered To heading. Unfortunately, Windows XP doesn’t provide you with a tool for changing this registration information. However, you can alter the registration information by editing the registry.

Follow these seven steps to alter the information:

1. Launch the Registry Editor (Regedit.exe).

2. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\Current Version.
3. Locate and double-click the RegisteredOwner value.
4. When you see the Edit DWORD Value dialog box, change the Value Data setting to whatever user name you want, and click OK.
5. Locate and double-click the RegisteredOrganization value.
6. When you see the Edit DWORD Value dialog box, change the Value Data setting to whatever company name you want, and click OK.
7. Close the Registry Editor and restart Windows XP in order for the changes to take effect.

Note: Editing the registry is risky, so be sure you have a verified backup before saving any changes.