Nginx- error: bind() to 0.0.0.0:80 failed. permission denied

If the port is already in use, you can change the default port of 80 to a different port that is not in use (maybe 8070). In conf\nginx.conf:

server {
    listen       8070;
    ...
}

After startup, you should be able to hit localhost:8070.

tl;dr

netsh http add iplisten ipaddress=::

Faced similar issue. Run the above command in command prompt.
This should free up port 80, and you'd be able to run nginx.

Description:
netsh http commands are used to query and configure HTTP.sys settings and parameters.

add iplisten : Adds a new IP address to the IP listen list, excluding the port number.
"::" means any IPv6 address.

For more netsh http commands refer the netsh http commands documentation.

Hope this helps!!