Tip 47: Re-activate Windows XP Installation after re-install

If you plan to reinstall XP on the same hardware, you can avoid having to activate the newly installed system again by backing up the activation status and then restoring it after you reinstalled the OS.

To save the activation status, back up the wpa.dbl file from the %systemroot%\system32 folder to a disk or other location.

After you reinstall the OS, perform the following steps:

  1. Start your Windows installation in Minimal Safe mode.
  2. Move to the \%systemroot%\system32 folder.
  3. Rename wpa.dbl to wpa.noact (or something of your liking).
  4. Copy your backed up wpa.dbl file to the system32 folder.
  5. Reboot your system as usual.
This procedure is not a hack to avoid activating installations in the first place and will work only for an XP installation on the same hardware that you’ve already activated.

IMPORTANT DISCLAIMER:
THIS IS ONLY FOR THOSE WHO HAVE INSTALLED A LEGAL COPY OF WINDOWS XP ON THEIR MACHINE AND HAVE ALREADY ACTIVATED THE SOFTWARE THROUGH MICROSOFT. PLEASE UNDERSTAND THAT IF YOU INSTALL OPERATING SYSTEM ON ANOTHER MACHINE (MEANING MORE THAN ONE) YOU SHOULD HAVE A VALID LEGAL COPY AND LICENSE AND SHOULD ACTIVATE THAT COPY THROUGH MICROSOFT.