Is there a way to fix a corrupt password protected Excel file?

Question

I have three password protected Excel 2007 (xlsx) files that I use regularly but today when I went to open them (after I enter the password) it gives me an error that the files are damage or corrupted and cannot be opened. My other Excel files seem to be working. I've done a system restore using XP and some other things but nothing has worked. Can any give me ideas? And does anyone know what would cause such a specific problem?

Answer 1

You have already identified and used the surest way to avoid problems in the future.  Keep backups always including one in a private folder that does not have any passwords set.

Discovering, for certain, what went wrong after you have fixed the problem via recovering backup files would be very difficult and at best it would only show how your problem happened this time.  The next time would likely be different.

The most likely general source of the problem would be that password protected files were not closed properly or something unexpected happened during an attempt to close a password protected file. But I not sure how that helps you to determine a way to avoid the problem in the future.