After installation of Windows XP, you need to activate it with Microsoft over the internet or the telephone. But you do not have to do so every time, you re-install Windows XP. You can backup Windows activation after you have activated Windows, and later use the backup to re-activate Windows after re-installation of Windows XP using the following process :
Backup Windows activation
- Open Start Menu → Run, type %windir%System32 and press Enter
- Make sure you have Show hidden files and folder enabled as described in this article : Display hidden files and folders in Windows XP.
- Copy the files Wpa.dbl and Wpa.bak to a CD, another partition, hard drive or a USB disk.
After you re-format the hard disk or Windows partition, and re-install Windows XP, you can restore Window activation in the following manner :
Restore Windows activation
- Restart your system, and as your system boots up press F8 repeatedly to access the boot options.
- From the menu options select to start Windows in Safe Mode.
- After Windows loads in safe mode, open Start Menu → Run, type %windir%System32 and press Enter
- Copy the backed up files (Wpa.dbl and Wpa.bak) to the System32 folder. You man not find the wpa.bak file on your computer and that is ok.
- If prompt comes for over-writing files then choose Yes.
- Restart Windows
Note that this will not work if you do not have an administrator account or you have modified/changed hardware.