To understand how undeleting a file in Windows would work and the odds of success, it is helpful to know how a file is deleted.
Say you have a file on your hard drive. It could be a text file or a bitmap image, anything like that. Your file is allocating a certain amount of space on your hard drive, a physical location on the disk. The operating system (Windows) points to this file using an address, just like a house’s address. When you delete the file, the address is actually deleted, so there is nothing pointing to this physical area of the disk. The contents of the file are still there, but they are in an area marked as free, so they could be overwritten. As long as nothing has overwritten that area, it is possible to undelete files by recreating the address pointing to that location. Because of this last point, it is important to get to the recovery process as soon as possible.
One such tool that works for recovering deleted files is Free Undelete. It’s a very simple interface, but it does exactly what it promises. Install this to your computer and run it (as local admin) where it will scan your drive for deleted files. You can then restore them to a separate drive (flash drive, mapped drive, etc.). You’ll want to run FreeUndelete as quickly as possible after the accidental deletion and emptying of the Recycle Bin so that the file does not get overwritten.