You can launch the Power Data Recovery by double click "Power Data Recovery" icon on the desktop. You can also launch the application by going to:

Start > Programs >  Power Data Recovery > Power Data Recovery  

When you have launched the Power Data Recovery, you'll see the main Power Data Recovery window.

Now, you have to choose which kind of recovery you need.

Just press "Undelete Recovery", or "Advanced Recovery", or "Deep Scan Recovery", or "Resume Recovery".
Choose "Undelete Recovery" if you want to recover files that were intentionally (or accidentally) deleted.
Choose "Advanced Recovery" if you want to recover files on the re-format or damaged volume.
Choose "Resume Recovery" if you want to resume the last recovery result.
If you have lost partition or cannot find the volume you want to recovery in "Advanced Recovery" module, you should scan physical device to find the partition in Advanced Recovery module.

You can go back to this choice at any time later - just click "Home" page button at top of the main window.