Problems with setting up security tab

[Sophia]

Hello,
I hope somebody can help me with this, I am getting crazy!
When I click on the security tab on the WSAT page (Website/ASP.NET
configuration) I get the following message:

"There is a problem with your selected data store. This can be caused by an
invalid server name or credentials, or by insufficient permission. It can
also be caused by the role manager feature not being enabled. Click the
button below to be redirected to a page where you can choose a new data
store.
The following message may help in diagnosing the problem: Unable to connect
to SQL Server database. "

I have SQL Server 2005 running (Windows authentication)
In VS.NET I can connect to it!
I am logged in with administrator rights
I ran the tool to create the security database.

Please, can anybody help!
Sophia

 

[Sophia]

I found the solution myself. Here's the link that explains everything:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpag2/html/paght000013.asp