How can I rescue data from a corrupt Excel 2007 .xlsx file?

PaulHar23

Estimable
Jun 27, 2015
1
0
4,510
We lost a folder full of excel files last week. We were able to recover all of the files that were in the Excel 2003 .xls format but have been unable to even extract data from the lates two files from May and June that were save in the new 2007 .xlsx format.
We've tried the Excel 2007 recovery features and every commercial product we could find that claimed to recover the new .xlsx format including Recovery Toolbox, Excel Fix, and many many others. Nothing has worked so far.

At this point all we need from the file is a list of names and we can recreate the rest from that. Any help would be greatly appreciated. We've recovered 48 copies of the same file but not one of them has worked.