zing_deleted

when you say it will not boot do you mean it wont load windows ? does it post? when you say the drive is fine in daughters machine does it boot windows or as a slave?
Could boot from xp cd and goto os recovery and try fixmbr command

Edit if you cant do this in main machine do it in daughters it should find the boot record. Also run scan disk on daughters machine if you can or chkdsk in recovery