Undelete My Files is a quick and effective way to restore accidentally deleted files. It can also recover files that have been emptied from the Recycle Bin, permanently deleted files within Windows using the Shift + Delete, and files that have been deleted from within a Command Prompt.
A deleted file is essentially an area on disk designated as free and ready to accept data (such as contents of some other file). Luckily, unless the area has already been overwritten, it still holds the contents of the deleted file. Due to this fact it is possible to undelete files.
As soon as you discover that vital files have been erased, the most important thing is to prevent erased files from being rewritten. Minimize (and whenever possible, stop) any activity on the disk you are going to undelete files from! Remember that writing to that disk can damage the contents of the deleted files. Examples of disastrous activity include: copying files to the disk, installing programs there or running programs that use the disk as their swap media.