It sounds like your file associations somehow got messed up. The default install path for Excel 2010 should be: C:\Program Files\Microsoft Office\Office14\EXCEL.EXE

But to fix the problem permanently, you will need to change the default program (.exe) associated with the Excel file extension. You can see a good tutorial on how to do that here: http://pcsupport.about.com/od/fixthe...-windows-7.htm

Hope this helps.

Joel