A Unity ID allows you to buy and/or subscribe to Unity products and services, shop in the Asset Store and participate in the Unity community.
Separate names with a comma.
OK, so I uninstalled the latest version of Unity and Re-installed with the base version 5, and it loaded just fine. I hope this helps!
I'm trying to do a fresh install with 5.0.0. If it works, I'll re-post.