AutoRecover
Don't miss that you can set your Excel spreadsheet to automatically save copies of itself at fixed intervals in time. This can be a great asset for the forgetful attorney who fails to save her or his work. It can also act as a safeguard when you're making a lot of changes with a crowded spreadsheet that is prone to crash.
Go to File . . . Options . . . Save. Check off 'Save AutoRecover information every . . . ' and set how often in minutes you want Excel to save your workbook.
If you make the setting for 2 minutes, and you have made a change within that time interval Excel will automatically save a copy of spreadsheet. If another a change is made between the beginning of the third minute and the end of the fourth minute, another copy of the spreadsheet will be saved.
If the 'Keep the last autosaved version if I close without saving' box is checked, Excel will backup only the last version you neglected to save.