Rarely will you see a Microsoft Word document that appears as a zero-byte file; even a Word document that is blank still registers approximately 12.5KB. A zero-byte file is never a good sign and often points to a corrupt or damaged file or a bad sector on your hard drive or flash drive. By default, these causes mean that the contents of the zero-byte document are wiped out. While some programs can restore a corrupted file, they do not always work perfectly; some documents may be partially restored, and others may not be restored at all.
Corrupt or Damaged File
In most cases a Word document that appears as a zero-byte file is corrupt. Files will occasionally become corrupt when the machine malfunctions in some way while you are saving your document—for example, when the computer loses power and shuts off, or Microsoft Word freezes and crashes. If you've backed up your hard drive you may be able to restore your computer and gain access to an undamaged version of the file, but this is not a guaranteed fix.
Bad Drive Sector
A hard drive is like a record in a record player; files are saved on platters (records) and read by a read-write head (the arm and needle on a record player). As with a record, if any nicks or scratches appear on the hard drive, it will lose functionality. Also, some hard drives are inherently flawed, and you may not stumble upon a bad sector of a hard drive until you have owned your computer for several years. Flash drives do not save data in the same way as a hard drive, but they are still susceptible to having bad sectors in their circuits and boards. In either of these cases, if your file is saved to a damaged or faulty section of the hard drive or USB drive, it can appear as a zero-byte document. In these cases, if you wish to recover your data, you will have to send your hard drive or flash drive to a clean room for professional data recovery.
Professional Data Recovery
Professional data recovery is an expensive option for restoring your files from a faulty hard drive or flash drive. It involves dissecting the drive and imaging either the hard drive platters or the flash drive memory boards in an attempt to retrieve as much data as possible. This is an expensive option. Because each case is unique, you should contact a data recovery center for an estimate.
Preventing Data Loss
The simplest way to prevent data loss is to save multiple copies of your important Word documents. Keep one copy on your main hard drive, and keep a second copy on a USB flash drive or an external hard drive. If your Word files are particularly important you may wish to keep a third copy as well. This way, if something does happen to your original file, you have a backup that contains the information you need.