Cant open Execl file-Not a valid win32 Application
 

I am using 2007 version of Excel and vista. In the past when I used Windows
XP and 2007 version Excel I was able to open a non Excel file in Excel with
no problems. Now it gives the message "%1 is not a valid win32 Application".
If I save the file to a directory I am able to open the file. I have changed
the settings in tools "ignore other applications". Any help, please
Thanks