Its an known issue that excel cannot open new instance when ever you open file or excel application in windows vista\7.
Only work around is start> all programs> MS office> excel
No of times you open or launch app like this will open an new instance of excel.
The suggestion given by RON AT BUY is for windows XP and the file types feature was removed from windows vista on wards.
Keep Eye on your TIME, Not on your WATCH!
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This is certainly much easier than the other methods and it worked on Windows 7 with Office 2010.
This method also works to bring up a separate window of Windows Explorer which shows all your files and folders. And it will bring up as many new windows as the number of times you go to the Start menu and click "Documents" on the right side of the pane.
Thanks for the great solution.