You want to get rid of this error while you can only open excel files when Excel is opened?
Check those printscreens to solve it:

About Benwake
I'm Benoît, working as a System Engineer for a big company. Webdesign is one of my biggest passions. I hope you'll enjoy this website. Do not hesitate to contact me if you have some questions about something or if you have comments (info@benwake.com). I speak fluently English, Dutch, French and German