Thank you for your question.
I would like to suggest you to check below Troubleshooting steps.
- In Windows 10 , Please make sure IIS is Uninstalled completely , you can verify from from Program and Features ->Turn on Windows features on or off
- In Windows Server , Open Server Manager - > Click on Manage -> Remove Roles and Features- > Features- > Untick IIS hostable core.
- Check where 443 port is being used on your server.
3.a Type netstat -aon | findstr '[port_number]'. Replace the [port_number] with the actual port number that you want to check and hit enter.
3.b If the port is being used by any application, then that application's detail will be shown. The number, which is shown at the last column of the list, is the PID (process ID) of that application. Make note of this.
3.c Type tasklist | findstr '[PID]'. Replace the [PID] with the number from the above step and hit enter.
3.d You'll be shown the application name that is using your port number.
Hope this helps,