Reset sa password when you can't connect

I'm not sure what happened but I can't connect to server. The error resembles the sa password is not correct. I'd like to reset it but can't. I tried logging in with my windows authentication but that didn't work. I tried replacing the server name as ADMIN:'Server Name' like a thread here said but couldn't get logged in. Capture

Check Windows firewall. You may need to open port 1433. In any case that error is a network related error.