Unable to browse default IIS website on Windows instance on AWS
Solution 1:
The first thing you need to do is assign an elastic IP address to your instance.
Next, you need to make sure that the security group assigned to this instance has whatever port is added for inbound connections for whatever port you have created the website on(80, 443, etc.).
You also want to make sure that this port is open on your Windows firewall.
Solution 2:
Because this is still relevant and confusing as ever, here is what I had to figure out. Using the accepted answer, also make sure you assign your security groups to your instance. You do this by using the Actions menu for the selected Instance.