Excel Template Startup

I have an Excel template file that starups automatically when I start Excel.
I stored my template file in the Startup folder; path C:\Program
Files\Microsoft Office \Office11\xlStartup\MyTemplate.xlt.

I exit the program and startup Excel, it opens the template but with the
extension of xlt instead of xls. How do I get the template to open as an xls
file?

Thank you... Elaine