Can i recover files?

Hi All, hopefully you can help me with my dilemma…

I thought i would have to reinstall windows xp and therefore format my hard drive so i moved files which were precious onto my mp4 player which doubles as my temporary external hard drive.

Thankfully i resolved the problem and did not have to reinstall windows, however, when i tried to move the files back onto my computer again, the contents of the single most important folder (containing personal documents, music, pictures and other folders) had been replaced by files of the same name as the folders, 64kb in size with no extension.

I forget whether I cut and paste or moved the files.

Is there any way I can recover these files using software?

Any help would be most appreciated.

CJ