|Either your installation is corrupted, or you installed 64bit windows XP. |
Why did you reinstall windows? You may have a memory problem or a hard drive problem if the newly installed windows is corrupted.
type winver in your run box and let me know what build is installed.
open your run box, type cmd then hit enter. in the command box type chkdsk C: /r
then reboot your comptuer.
after that finishes,
open your run box and type sfc /scannow
if that ask for the windows disc put your disc in an let it finish.
reboot, now try to install SP3 again.