I'm really not a person that can answer your question, because I know nothing about XP Mode. However, your use of the word "deleted", rather than "uninstalled"
, makes me wonder if you looked in the Recyle Bin? Since I imagine that you did, I would suggest using a program designed for recovering lost files, like O&O DiskRecovery. It costs about $100, but a file containing 10 years of data might be worth the cost.
EDIT: There are freeware recovery tools available, but I'm not familiar with them, so I can't recommend any of them.