1.. Insert and boot from your WindowsXP CD.
2.. At the first R=Repair option, press the R key
3.. Press the number that corresponds to the correct location for the
installation of Windows you want to repair.
Typically this will be #1
4.. Type bootcfg /list to show the current entries in the BOOT.INI file
5.. Type bootcfg /rebuild to repair it
6.. Take out the CD ROM and type exit