Can not open the Password file
 

I have a problme in opeining password protected Excel files.
I am using Excel 2007. I have received a file from some one..its is in excel
2007 format & its is password protected. When trying to open that file its
giving the message "Excel cannot open the file because the file format or
file extension is not valid. Verify that the file has not been corrupted and
that the file extension matches the format of the file."

I can open this file in any other computer, except in my computer.. can you
pls help me what changes needs to be done in "Option" to open this Password
protected file.

I can open any excel 2007 files, except password protected files..

Regards,
Vishu