Its very unlikely you have lost the data.
Try and recall a file name that you know, do a search for it and you'll probably find it is in the directory: -
C:\Documents and Settings\.............
Which is the collection of every users Documents and Settings you would know as "my documents".
Especially look under the directory of the same name as your old users and in there you'll find all the old documents/music everything.
Window reinstall/fix rebuild or whatever does not remove this unless you do an image restore. This like a format simply overwrites EVERYTHING with the information you had when you took the image backup.