Sound and mic Problem in dell Latitude E6410

I recently bought a Dell Latitude E6410 with Win 10. I have problem with its sound and mic. When I active the mic, I don't have sound on internal speaker, when I fix the sound, then the mic doesn't work. If I add an external mic it does work with sound together but not in all apps. For example, they don't work together on Skype. 

When I used Dell driver checks, it showed me the BIOS needs to be updated, but when I want to update it gives me error. 

Appreciate any help. 

Thanks.