Cannot connect to UserPC\SQLExpress

I just installed SQL Server Management Studio 开发者_开发知识库Express 2008. For the username 'sa', I tried to change the password and login through SQL authentication but it failed.

I tried to create a new new user too and login. While I try to login in to the SQL management Studio, this error is given - > Screenshot: http://i.stack.imgur.com/nzq6i.jpg

What's going wrong?

Verify that "SQL Server and Windows Authentication mode" is selected in the Server authentication section of your server's Security properties.

Looks like SQL server is not properly installed.check computer>manage >services and applications ... if you can see SQL server under that its install is successful. if not the problem is with the installation

Try restarting your SQL Server. Looks like the service is not accepting the connections.