I'm a new user. I downloaded "sam-windows-2015-6-30-r4.exe". I ran the installation program and got to the Registration Window. I entered my email address and clicked Register. After 30 seconds, I received the following error message: "Registration failed with error code-1. Please check your internet connection." I have an internet connection. I checked with our corporate network IT people and they could not see any problems with my network connection to the internet. We talked about proxy settings and they didn't think proxy settings would be needed.
It is possible that the NREL server was having trouble when you tried to register. Please try again today, and let me know if you continue to have trouble.