It can be such a bugbear when you suddenly lose that document you were working on halfway, or saved it somewhere with an impossible to remember location. Here are a couple ways to salvage something before pushing the panic button:

1. Search Party Rescue
   In Windows, click Start, Search, All files and folders.
   Type what you remember of the name or simply *.doc to get all your Word documents.
   Select My Computer under Look in, and then under More advanced options, make sure Search hidden files and folders is checked.
   Then hit Search.
2. Check your Recycle Bin
   Open it up and look through whatever files you’ve got. Did you find it? If so, right-click and choose Restore. Then if you’re not sure where it actually restored to, perform a search for it.
3. Magic of AutoRecover
   Sometimes if Word crashes or closes unexpectedly, it’ll still save what you had. Re-open Word. If a Document Recovery task pane comes up, double-click your document to open it and immediately Save As.
4. Search for AutoRecover files, DIY
   In Word, go to Tools, then Options.
   Under the File Locations tab, double-click AutoRecover files and make a note of that path location.
   Click Cancel and Close.
   Open up that folder in My Computer or Windows Explorer and search for any .asd files. (Or another way to do this would be to run a search similar to step one but with *.asd instead of *.doc)
5. Check the original folder for any .wbk file
   In Word, click File, then Open.
   Navigate to the folder you think the file used to be located in and make sure All Files *.* is selected.
   Is there any .wbk file there? Select it and see if it’s what you’re looking for.
6. Search for *.wbk
   This step is the same as the first search party step, but now search for *.wbk files. You might find a few. Open them up, one by one.
7. Search your temporary files
   Again, this is like step one. But search for *.TMP files this time. You’ll come up with a lot, so change the When was it modified? to the last 48 hours.
8. Search MORE of your temporary files
   Some temporary files like to be unique. Search for those with ~*.* instead.
9. Open up C:\Documents and Settings\*USER*\Local Settings\Temp
   This is a hidden folder, so you’ll probably have to use Windows Explorer. Hit Start, then All Programs.
   Go to Accessories, then Windows Explorer. Navigate to that folder, where *USER* is your username that you login with. Pray that it is there!

If the file has been completely deleted with no traces, the best bet is to use a file recovery software.