Does SQL Server set up to allow SQL Server Authentication?

>When I select this choice (Right Mouse Click on the Server Name (local) | Edit SQL Server Registration Properties, "Use Windows Authontication" is selected.
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>I want to change it to "Use SQL Server Authontication". When I click on this choice, the User Name and Password fields are enabled. I enter a user name and a password, click on Ok but I get error that
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>SQL Server Registration Failed bacause of the connection failure
>displayed below..
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>Actually nothing is displayed below. What am I missing here?
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