SQL Server Windows Authentication

I'm trying to connect to a remote SQL Server Express machine using Windows authentication. I´m logged on with a user with username Administrator, but when logging in, I get the error message:

Login开发者_开发知识库 failed for user guest ... 

Why is not using the Administrator account?

Thanks in advance.

For Windows Authentication to work, the target machine has to be on a domain where your Windows credentials will be recognized. If the server is outside of your organization's control, it will not recognize your credentials and you will have to use a Sql Server user ID and password to log in.

SQL Server Express by default only allows local connections - you can enable it, but you have to explicitly do so.

See these:

• SQL Server Express team blog: how to enable Express to accept remote connections.
• How to enable Remote Connection on SQL Server 2008 Express