This problem has completely shot my entire day. I reformatted my old windows XP comp and tried installing XAMPP only to find that when i try to start Apache xampp claims por
Try finding the Service running on the PID that is blocking the service from Task manager->Services
In case this isn't of help go to Task Manager->Services
Go to the Services button on bottom right of window and stop the Web Deployment Agent Service. Retry starting Apache . That might solve the problem.