The file format for xl97 to xl2003 is the same.

Users of xl97 should be able to open any normal workbook saved in any of those
versions.  (Yes, there may be functions/code that break, but that shouldn't stop
the users from opening the file.)

I'd start by having the xl97 user open excel in safe mode:
close excel
windows start button|run
excel /safe
(and hit enter)

Then file|open your workbook to see what happens.

Maybe it's the user's pc--maybe it's your file.

If you think your file is corrupted and xl97 can't open it...

Lots of people have praised OpenOffice.org for saving their data and code.
http://www.openoffice.org, a 60-104 meg download or a CD

There are commercial recovery services.  I've never used it, but you might want
to check into:
http://www.officerecovery.com

And sometimes newer versions of excel can open files that older versions can't.
(And sometimes just different versions may work, too!)

Hi Craig

Excel 97 open all kinds of Excel workbooks, it is not the question of file
format.

I see two problems here:
- Some of your VBA probably addresses properties and methods added after
version 97. That code will err and stop.
- You are using "additional controls" like the Cdlg. Welcome to Dll Hell my
friend. I believe this is the reason for the "won't open" problems.
Additional controls require that the user have them installed and often also
licenses to run then i "design time". Problem always.

Additional controls do add lots of useful functionality to Excel files, but
this is rarely the case with the Cdlg. What are you using it for ? If it is
file open/file save then workarounds are really easy and your four months'
work is out of danger.

HTH. Best wishes Harald