The SSL certificate is still bound to port 443 after you disable the WinRM HTTPS compatibility listener

With Windows Remote Manager 2.0 (WinRM), you can receive the incoming HTTPS requests on port 443 on a computer that is running Windows Server 2008 R2 if you enable the HTTPS compatibility listener. The HTTPS compatibility listener creates an SSL certificate and then binds the SSL certificate to the port 443.

When the compatibility listener is disabled, WinRM no longer accepts any incoming requests. But the SSL certificate is not removed. If the WinRM compatibility listener is disabled, this behavior prevents a bind of the same certificate to a different application such as IIS.