Did you have a backup? Windows Restore point created? If not, that data has been deleted if you reformatted over it. There are options available if the data is worth it, but most of them are not cheap and not guaranteed to work:
Actually, it may be not so much expensive if you try to recover the files yourself. The most important question here is have you written something on the disk after format? If no, chances for success are high. This article explains what to do in your case: So, what do you have to do to get deleted files back?