Windows Update is a useful feature but to ensure your privacy you may not want to register your personal details before being able to use it. With this tip you can bypass the registration process.

1. Open the Registry Editor click on the Start button on your taskbar, then click on Run and type "regedit" and click on OK to start the regedit utility.
    
2. Expand HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion (see picture 1).
   
   

   Picture 1

3. Create a new STRING value called "RegDone", or modify the existing value, to equal "1".
    
4. Check that the key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Welcome\RegWiz exists, if it doesn't then create a new key.
    
5. The modifications you made will be in effect after you reboot your PC.

Note: This will not bypass Windows XP product activation which is compulsory on all consumer versions of Windows XP Home and Professional.