Excel Auto Backup

To have Excel create a back-up copy of the file do a Save As on the file and on the Save As window click Options and check "Always Create Back-Up". (In E2K it?s under Tools>General Options in the Save As dialog box.
This will create a back-up copy each time the workbook is saved.
You can, also, use the Add-in AutoSave. In E2K look at the Tools menu. If it doesn't show, go to Tools>Add-Ins. I think it was on the installation CD for Office 97, but I don't remember.
This will save the Workbook at specified intervals.
To create a backup when ever it?s opened, Set Save As to create a backup, then write a macro like:

Sub Auto_Open()
ActiveWorkbook.Save
End Sub