I want to know what the impact would be if I were to enable TLS 1.2 on Windows Servers and disabled older protocols. I enabled TLS 1.2 on my Windows 7 Laptop manually running the Microsoft Fix It script and it broke my VPN connection, but that's for another thread.
If you only enable new protocol, then there is no impact for existing applications as long as you do not disable others. SSL/TLS protocols in Windows are implemented side-by-side and one protocol do not affect other protocols. But if you disable any other protocol, applications may fail if they explicitly rely on a disabled protocol.