what you have done in the past is not reformat the hard drive, but rather reinstall windows 'on top' of the current installation. effectively Windows is re-installed (well, not exactly) but all the files previously on the computer should still be there, including the old users' Documents and Settings.
this time, you apparently did re-format the partition.
barring using special recovery software like redk said, your files are gone
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In the land of Mordor, where the Shadows lie
M.C. Escher - Reptilien