Some application programs - not all - are designed to create temporary files, sometimes referred to as work files. A temporary file usually is updated as you proceed with your work and keeps part or all of a document's data, while the document is open. Temporary files are automatically deleted when you quit the program with a normal procedure. After an unexpected quit, a Force Quit, or a restart after a system crash, however, these temporary files typically do not get deleted and remain somewhere on your hard drive.

These temporary files are expected to contain data from the document you were last working on before the crash, even if you had not yet saved the data. More often, though, these temporary files will be useless, containing virtually no data at all. Still, it can't hurt to check them.

Temporary files are not shown on the Finder's desktop or in most Open or Save dialog boxes so you won't use them by mistake during normal operation of the Macintosh. For example, deleting a temporary file while the application that created it is still open (assuming the Macintosh lets you do this) could cause a system crash! The downside, however, is that their invisibility makes these files more difficult to find when you do want to use them.

There might be too many temporary files on your disk left over from system errors that are now ancient history. These will obviously be of no value to you in recovering data from your current system error. However, you are looking for the one that contains data from the document you were working on at the time of the crash. Often you can figure this out by the name or by the date of the file, which tends to give away its origin and nature (such as Word Work File for Microsoft Word 6.0 temporary files). To be certain that you ferreted out all of these files, look for both visible and invisible temporary files.

After a system crash, the first place to look for visible temporary files is in the Trash. If you are using System 7, the system software creates a special folder called Temporary Items. Any programs that are written to utilize this folder place their temporary files into it. This folder, and the files within it, are normally invisible.

After a system crash and a subsequent restart, however, the Macintosh automatically places all the items in the Temporary Items folder into a new folder called "Rescued items from [the name of your disk]." This folder is visible and is placed in the Trash. It contains the files that were in the invisible Temporary Items folder at the time of the system error. On Power Macintoshes, the folder may simply be named Temporary Items. So, if you find the Trash can bulging immediately after a restart, double-click the Trash icon to open its window. If you find a Rescued Items folder in the Trash, remove it and place it in any other location. The temporary files in the folder should all be from applications that were open at the time of the system error, so it should be relatively easy to check for the ones that are useful to you.

Occasionally, there may be visible temporary files on your disk that do not make it to the Trash. They are typically in your System Folder, in the same folder as the application that was active at the time of the crash, or at the root level of your disk. You can use the Finder's Find command to help locate these temporary files, if necessary. If you are unsure of what the name of the temporary file might be, try wild search.