Open Without Password Field Prompt - Office 2007
Environment: MS Excel 2007
Excel password-protected file without password prompt when startup, which made the file unable to open.
I suspect it caused by the file is saved from Office 2010.
Finally, I fixed it after install the patch via the link below:
http://www.microsoft.com/en-us/download/details.aspx?id=3
It is Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats
if you are using Office 2007, and encounter the same problem, give a try