SQL Server Connection Error

If you haven't already received an answer to this, I tested it out and I get the 18456 error when my SQL server is set to "SQL server and Windows authentication" and my connection string for my application is set to "Windows NT authentication". Check to make sure both your server and your application are using the same authentication.

Hi guys and thanks for starting this thread,

I have experienced the same problem -SQL Server Conn Error, but in my case I used windows authentication, and local system.

But the interesting part is that it only happened after I installed the XP Pro 64 bit (before I had 32 bit) and reinstalled VS 2005 and SQL developer version. While VS works fine I can't access or create SQL database because every time i click at server name combibox I get a blank field and the massage no Server connection. (without error type)

I tried to contact Microsoft technical support with regard to this question but they left me bewildered when they said that i had to pay 380$ for their help on this issue, what's unbelievable bearing in mind that XP 64 bit cost 215$. So if anyone can help or has experienced the same problem it would be highly appreciated.

How are you connecting to your SQL Server?

What type of authentication are you using?