How to restore XP activation status information after a reformat

• Double-click My Computer, then double-click on the "C" drive.
• Navigate to the C:\Windows\System32 folder.
• Locate the files named "wpa.dbl" and "wpa.bak" and copy them to a safe location such as a USB key or CD.
• Reformat your disk and reinstall Windows XP on your reformatted hard drive, click "No" when asked if you want to activate Windows.
• Reboot your computer into SafeMode (press F8 as Windows is booting up to see the Windows Advanced Options menu and select SAFEBOOT_OPTION=Minimal)
• Double-click My Computer, then double-click on the "C" drive again.
  Navigate to the C:\Windows\System32 folder again.
• Locate the files named "wpa.dbl" and "wpa.bak" (if it exists) and rename them to "wpadbl.new" and "wpabak.new"
• Copy your original "wpa.dbl" and "wpa.bak" files from your USB key, CD or DVD or other location into the C:\Windows\System32 folder
• Restart your system.