To safeguard against data corruption, accidental deletion, or lost files, it is a good idea to back up important Excel documents.

 

The first step to creating a backup file every time you save, is to display the save as dialogue box by choosing File->Save As from the menu bar.

 

 

In the save as dialogue, select the General Options item from the Tools drop list. This will display the Save Options dialogue box.

 

Put a checkmark in the Always create backup check box and then click the OK button.

 

Now, every time you save your workbook a back up copy will be saved.

 

If you open a workbook, and make changes to it, the original version of the workbook (before the changes) is saved as a backup. This means that the backup is always the most recent earlier version of the current workbook. This is great for recovering from unwanted or inaccurate modifications. Plus, you have a copy of the worksheet (minus your latest changes); in case you lose or delete the original. When you create automatic backups this way, the backup files are saved in the same folder as the original files. The backup files will have the file extension xlk instead of xls.