Issues with connection in SQL Server 2008 Management Studio Express

Today I've installed the SQL Server 2008 Management Studio Express. As I know, on the start up there is a login screen where I can choose betweeen the authentication and credentials. Now I have startet SSMSE and I cannot connect to my Server(runs locally). I have开发者_如何学Go tried to use my Windows account and also the "sa" account. Both doesn't work. Does anyone know how to fix the problem?

I've solved my problem. I've reinstalled the SQL Server, after that it works.

This.