To use Windows Update, you have register XP. If you want support from Microsoft without having to give them you private data (name, email, phone, ...), you can use the following registry hack to fool XP into thinking that XP has been registered. This is essentially the same hack used in Win98 to block registration. Don't be confused - this is not blocking Product Activation. This will only work if you have not installed XP. If you have installed XP and there is internet connectivity, you already are registered.

• Your PC must not be connected to the network.
• During XP setup answer no when setup asks you to use Windows Dynamic Update.
  Dynamic update connects to Microsoft to register XP.
• Once the installation is completed, reboot to Safe mode.
• Click Start
• Click Run
• Rename %systemroot%\System32\regwizc.dll and %systemroot%\System32\Dllcach\regwizc.dll to regwizc.dll.bka or whatever.
  By renaming the regwizc DLL, it blocks other windows components from registering XP to Microsoft.
• Apply registry hack:

  Hive: HKEY_LOCAL_MACHINE
  Key: SOFTWARE\Microsoft\WindowsNT\CurrentVersion
  Name: RegDone
  Type: REG_SZ
  Value: 1 its registered
  

• Change the IE home page to something besides Microsoft's web site.
• Reboot to Normal mode and reconnect your nic card before the XP Windows GUI loads.

The Mastering series is quite good.

Keywords: Windows XP registry tip, disable XP registration, privacy, RegDone, hack, regwizc.dll, regwizc, dll