You'll need to edit grub's configuration file
/boot/grub/menu.lst or
/boot/grub/grub.conf
Adding this stanza
Code:
title=WinXP
rootnoverify (hd1,0) #if windows is on 1st partition of 2nd drive
makeactive
chainloader +1
should do it.
edit: your english is much better than my Spanish or Mapuche