Are the files still in your Recycle Bin? From the sound of it, no. If not, you need a data recovery programme. There are some free ones on the snapfiles site. (Look under freeware - data recovery). There is also Tune Up Utilities click here which includeds an undelete programme.
You have a chance of recovering a deleted file using the above as long as the file hasn't been overwritten. All you do when you delete a file, initially, is to delete the path to that file and presumably the data recovery programmes can reinstate the path. The less you use your computer before attempting to recover a file the better, as there is less chance of overwriting the deleted file with new data.
Hopefully, someone else can give you more options in terms of the best data recovery programmes.