Unable to get connected to my EC2 instance (Windows)

Hello, probably the instance's subnet doesn't have an internet gateway as the default route (0.0.0.0/0) or the security group attached to the instance doesn't have RDP port open. Try to go through theses steps:

1. Create and attach an internet gateway
2. Create a custom route table
3. Create a security group for internet access
4. (if necessary) Assign an Elastic IP address to an instance

This doc describes the steps: Connect to the internet using an internet gateway