SQL Server does not exist or access denied

[Guest]

I am developing an application with dotnet using ASPX web pages to access SQL
2000 db on Win2003 server. Just before starting this project, I upgraded my
dotnet development application from 2000 to 2003 and asp.net from 1.0 to 1.1.

I have the simplest of all apps - a web page with a datagrid and one command

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
Me.SqlDataAdapter1.Fill(Me.DataSet11)
End Sub

I have copied the connection strings and commandtext etc to a 2000 dot net
environment and the datagrid dsiplays the contents of the designated table.
In the 2003 environment I the the Server does not exist

I can view the tables contents from the server tab. I then drag and dropped
the connection onto webform1.aspx. press the F5 - same response

Uninstalled enterprize architect thinking I might have installed in the
wrong order with respect to ASP1.1. Reinstalled enterprize architect - press
F5 - same response

No problem with access from query analyzer / excel / and provious versions
of dot net

Anyone have some good ideas?