Cannot connect to local sql server 2000 from VB.NET on pc ..

Hi

I just installed SQL Server 2000 to run locally on a WinXP Pro SP2 PC.
When I run the following VB.NET code:

Protected Const SQL_CONNECTION_STRING As String = _
"Server=localhost;" & _
"DataBase=Northwind;" & _
"Integrated Security=SSPI"

Dim connectionString As String = SQL_CONNECTION_STRING

Dim cnnNW As New SqlConnection(connectionString)

I can't connect to sql server.
This code works fine on a Windows 2000 Pro SP2 pc.

Thanks for your help.

Dee