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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