I have SQL Server 2014 on my Windows Server 2012 R2. I can connect locally to SQL Server from Management Studio using Windows Authentication.
I decided to switch to SQL Server Authentication (because I need access from other computer). I created new Login using Management Studio, but get error: Login failed when trying to connect.
Then I changed password for sa and tried login as sa, but again get the same error:

I restarted SQL Server, but it didn't help. What I do wrong?
From error log: Login failed for user 'sa'. Reason: An attempt to login using SQL authentication failed. Server is configured for Windows authentication only.
