This is a very strange issue that my customer is having.
Brand new PC (64-bit Dell), came with OEM version of Office 2013 Pro.
They open documents supplied by 3rd party. These documents have no extension in file name, but they are basically just text files. They were created by other application, exporting a report. So if we open the file with Notepad, it looks like a simple report text file with headers, columns, data, etc.
The requirement is to save these files with a password and pass them on to the end user. They have chosen Excel to do this with, since the end user may need to massage the data in the report.
Here is the issue: We open the file, Excel suggests columns and we accept all defaults. When we choose Save As, then choose Excel Workbook (*.xlsx), the file saves as a PDF document. It is still called filename.xlsx, but it has an Adobe Acrobat icon next to the file name in Explorer. If we double click on it, we get an adobe message saying invalid file format. So even with an xlsx extension, it still seems to be an acrobat document.
If when we Save As, we select Excel 97-2003 document (*.xls), everything works fine. This is only a problem when using current excel format.
Any suggestions? Thanks...
Ron Mittelman