My application uses Excel automation. Therefore, I reference the Excel Object Library. I have 2 questions...

1) How can I detect the presence of Excel on the system where my application is being used -- essentially to warn the user that the portion of the application that automates Excel will not work?

2) Since my application references the Excel Object Library, if the application is installed on a system that does not have Excel installed, will the application even run if Excel is not present?