I've coded a custom windows service that listens on TCP port 80 but when I try to install it on a Windows Server 2003 machine it fails to start because some other service is already listening on that port. So far I've disabled the IIS Admin service and the HTTP SSL service but no luck.

When I run netstat -a -n -o | findstr 0.0:80 it gives me the process id 4 as the culprit, but when I look at the running processes that process id points to the "System" process.

What can I do to get the System process to stop listening on port 80 and get my service to listen instead?

P.S. I should point out that the service runs fine if I install it on my Windows XP or Windows 7 development boxes. Also, I should specify that this has nothing to do with it being a service. I've tried starting a regular application that attempts to bind to port 80 on the Windows Server 2003 with the same outcome - it fails because another application is already bound to that port.