Port 80 Is Used by Another Service

Symptom: You can’t open the PerformanceGuard web interface after installation, or a PerformanceGuard Web Server service doesn’t start, because port 80 is already in use by another service.

By default, PerformanceGuard setup uses port 80 as the Primary Display Port and port 81 as the Secondary Display Port for the web interface. You set these ports in the Backend Properties step of setup.

Find the service that uses the port

1. Open an elevated Command Prompt (right-click Command Prompt and select Run as administrator).

2. Run this command to see which process listens on port 80:

   netstat -ano | findstr :80

   The last column is the process ID (PID). Look it up on the Details tab in Task Manager.

It can sometimes be difficult to see exactly which service uses port 80:

• If the PID is 4 (the System process), the port is used through the Windows HTTP service (http.sys). Typical users are IIS, SQL Server Reporting Services, and Skype. Run netsh http show servicestate to see which application has registered the address.
• In other cases Windows says that it couldn’t get ownership information. Then it’s also typically http.sys that uses port 80.

Solution

The easiest solution is to use another port for PerformanceGuard: run setup, and enter a free port as the Primary Display Port.

If you want to use port 80 for PerformanceGuard, move the other application to another port, or stop it:

• If a Windows service uses the port, and it isn’t needed on the computer, open Services (select Start, type services.msc and press ENTER), stop the service, and set its startup type to Manual. Otherwise, the service may soon start again.
• If the port is registered through http.sys, change the port of the application that registered it, for example the IIS site binding or the SQL Server Reporting Services web service URL.

Caution

Before you stop a service that uses port 80, make sure that it isn’t used for important purposes on the computer. Don’t disable the Windows HTTP service itself; other Windows features, such as Windows Remote Management, depend on it.