MYSQL shutdown nexpectedly

MYSQL is stopping unexpectedly but Apache PHP is still good why?
It said another program was on port 3306 so I went to cmd and found port 3306 and matched its pid (5104) with the task manager pid and it turns out that mysqld.exe was using pid 5104. What is the problem why does it say another program when it is using it?

In the log there was a line saying

Port 3306 in use by "Unable to open process"