Can't connect to EC2 instance no matter what I do.

To be clear, I can RDP and everything just fine. I'm writing software for a class that's supposed to communicate to a server. I launched a new EC2 isntance running Windows server and set security rules to allow ALL traffic, inbound and outbound. I have disabled the firewall on both the instance's machine and my machine, and allowed inbound and outbound rules for all ports on both. No matter what, when I check the availability of the ports on the instance, it says they are closed. I have an elastic IP set up on the port, and can easily ping it and get a response, but anything like telnet or ssh are entirely non functional. Also, when I try to test the instance with the software that I am writing, it is not timing out. The instance is actively refusing any connection that it receives. I tried doing user scripts from the AWS documentation to resolve this as well, and nothing has worked. What do I need to do to get this working?