IIS 

When the web site won't start - it may be because another process is already using the default port 80. If the application using it is valid you will need to use a different port by changing the binding of the website in IIS. Then you will access the website by specifying the custom port in the url. Example localhost:8082

Error

You will get an  error  error code 0x80070020 which translates to ERROR_SHARING_VIOLATION (The process cannot access the file because it is being used by another process.)

Resolution

Run the following command from a command prompt to find the PID of the process which is using TCP port 80 and/or 443. 

               netstat -aon | find ":80"
               netstat -aon | find ":443"

You will see an output similar to the following. Remember the actual PID will vary from case to case. 

               TCP    0.0.0.0:80             0.0.0.0:0              LISTENING       3604
               TCP    0.0.0.0:443           0.0.0.0:0              LISTENING       3320

Now using Task Manager you can easily find out to which process the above PID belongs and take appropriate action. 

MySQL

NOTE: not well supported by readers - see the Readers section below for more details.

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