Open Windows Explorer
Select "Tools"
Select "Folder Options"
Select the "File Types" Tab
Scroll down to find and select the XLS extension
Click the "Advanced" Button
Select the "Open" action from the list
Click the "Edit..." Button
Where is says "Application used to perform action:"
/e "%1"
to the end of the file path and then uncheck use DDE checkbox.
Refer more @
http://www.eggheadcafe.com/software/aspnet/29922442/how-can-i-open-2-excel-fi.aspx
