I have a very similar problem, which normally accurs when i have edited something, namely the httpd.cfg.
The solution i have found is to goto your xampp dir and click on the apache start.bat
If it does not start through the control panel chances are it will give you an error in this screen. Main causes i have found have been bad syntax and spelling mistakes in the cfg file.
Im no expert and am just going of my own experience, hope this help!