This article describes how Microsoft Excel saves files.
When you save an existing file in Excel, Excel creates a temporary file in the destination folder that you specify in the Save As dialog box. The temporary file contains the whole contents of your workbook. If Excel successfully saves the temporary file, the temporary file is renamed with the file name you specify in the Save As dialog box.
This process of saving files makes sure that the original file is not damaged. The original file is useful if the save operation is not successful.
When Excel saves a file, Excel follow these steps:
Excel creates a randomly named temporary file (for example, Cedd4100 with no file name extension) in the destination folder that you specified in the Save As dialog box. The whole workbook is written to the temporary file.
If changes are being saved to an existing file, Excel deletes the original file.
Excel renames the temporary file. Excel gives the temporary file the file name that you specified (such as Book1.xls) in the Save As dialog box.
Important Points About Saving
After Excel creates and saves the temporary file, all the changes are written to the temporary file.
If Excel cannot delete the existing file, you receive an error message. The original file and the temporary file both remain in the destination folder.
If Excel can delete the existing file, but Excel cannot rename the temporary file, you receive an error message. Only the temporary file remains in the destination folder.
If Excel saves a new file for the first time, Excel does not create a temporary file. Excel saves the file with the file name that you specified in the Save As dialog box.
For additional information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
214073 You receive an error message when you try to save a file in Excel
289273 Description of the AutoRecover functions in Excel 2002
324521 XL2002: How to Recover a Lost Worksheet or Lost Version of a Worksheet