Today I was working on a computer where opening the Mail Icon in the Control Panel just showed error “Application Not Found”. I removed MS Office 2016 and reinstalled it and it did not fix the issue. I had to go to Control Panel – Programs and click on MS Office 2016 and then select change and repair. It asked me if I want to do online repair so it can download needed files. It took a long time but this fixed the issue. Mail icon in the Control Panel will now open again with no error.