How to recover permanently deleted files?

When a file is deleted, even from inside the Recycle Bin or Shift deleted files, it doesn't actually vanish from the hard drive. Instead, after receiving the delete command, the computer merely changes the file's properties to make it invisible to the user. The space occupied by the file is also marked as empty even though it remains in that space. The file truly gets deleted from the hard disk only when the operating system reuses the space occupied by it and overwrites fresh data to that space.
Even then, there are possibilities that bits and pieces of the deleted file survive on the hard disk for years.
   Well,its easy to recover permanently deleted files using either of the softwares mentioned below:-

1.MiniTool Power Data Recovery
 It can not only recover the deleted files, but also help you save data from damaged partitions, pen drives, SD cards and CDs.
Download it from following link:-
http://download.cnet.com/MiniTool-Power-Data-Recovery-Free-Edition/3000-2094_4-10561431.html?tag=mncol;2

2.Recuva
 This software lacks the advanced features of MiniTool, but it is equally good at recovering deleted files. One advantage of using Recuva is that you can see a preview before saving the retrieved files.
Download it from following link:-
http://www.piriform.com/recuva