can you explain "corrupt"
a boot file missing ?
a virus killed it ?
the xp install cd is VERY notorious for not seeing that there is even a hard drive in the computer IF you put "grub" or "lilo" on the MBR
if you did this then see this help page ( yes fedora but ,applys to all *nix's )
"HOWTO Reinstall XP Without Destroying Fedora When the XP CD Balks"
or if using the MS bootloader to boot linux and the XP install cd sees the drive just MAKE SURE TO UNCHECK THE "CHECKED BY DEFAULT"
check box to install on the WHOLE drive
( assimilated by the Borg '- read [ MS] ')