You are installing Symantec Mail Security for Microsoft Exchange (SMSMSE). After you click Next at the Web Service Setup panel, you see the following error message:
1. Open a command prompt.
2. Run the following command: netstat -a -n -b.
4. Look for LISTENING lines for the port.
Here is an example:
This line shows that the process IMLogRelayService.exe is listening on all available IPs on port 8081.
Here is another example:
This line shows an operating system component listening on IP 127.0.0.1 on port 8082.
If there are any lines that show a process listening on an IP (or 0.0.0.0) for the port this condition is met.
The port selected in the Web Service Setup panel is in use by another application.
Select a different port for use by SMSMSE.