If files are deleted by: emptying the Recycle Bin, or by pressing Shift and Delete at the same time (to delete directly without going through the Recycle Bin), these files are not actually gone. Windows only changes the first character of the file name in the file storage system. Therefore, these files will be ignored by the operating system. Windows simply marks them as free space available for storage, allowing other files to overwrite them. To recover deleted files, you need tools to restore the original file names and remove these markers before Windows and other applications overwrite them.
The SystemWorks 2006 toolkit (priced at $70) from Symantec includes file recovery programs. Another trial program is EasyRecovery Lite 6 (priced at $89) from Ontrack. There is also a free utility called Restoration by Brian Kato.
If you are using Windows XP or Windows 2000, ensure that the programs you choose support the file systems you are using. These may be the FAT format (rarely used), FAT32 (commonly used in Windows 98, ME), and NTFS (used in Windows NT/2000/XP/2003). Windows 98/ME cannot read NTFS file systems. Windows NT/2000/XP/2003 can read all FAT, FAT32, and NTFS file systems. Unsure about the format of your hard drive? Select My Computer, right-click on the hard drive icon, choose Properties, and check the File System on the right.
When you format a hard drive, you create an index for each file on that hard drive. This index is known as the FAT (File Allocation Table) in FAT32 and MFT (Master File Table) in NTFS. If this index becomes corrupted due to a virus or is overwritten by formatting, Windows may not be able to find the files on this drive.
Data recovery programs can recover the FAT and MFT from backups or recreate the structure. If this index is irreparable, good data recovery programs can still identify and recover lost files.

EasyRecovery Lite not only recovers lost files but can also recover and partially repair corrupted files like Word and Zip. EasyRecovery Lite has a raw data recovery mode (RawRecovery) for damaged hard drives, where no folders exist.
Minh Phúc