I am running the new version of dotnetnuke, installing on a dedicated server running sql express on that same server.  I have enabled remote connections in for the sql server.  I have created a user name and password and given permissions to the network services account.  I cannot log into sql remotely from sql server manager express, and dotnetnuke cannot create a database during install either.  Both of these problems say they are due to failed log in.  Here is an example of the error

Connection Error(s):
Index #: 0
Source: .Net SqlClient Data Provider
Class: 14
Number: 18456
Message: Login failed for user 'NT AUTHORITY\NETWORK SERVICE'.

Of course the user changes when I log attempt to log in as myself but the error remains the same.  This isn't a firewall problem either.  I do not understand what is causing the error.  I have been working on this for a while and am about to throw the computer out the window so any help would be appreciated.  Oh I also gave an account to asp.net and IIS, those didn't help either (found that suggested on another forum.  

Thanks in advance. 

SQL database and website are on the same machine.  I am trying to do this from home but I do have access to computer with remote desktop and also plesk, so I can make changes on the server.  What do you mean by domain account and how do I set it up?  Right now I can't access sql server remotely but have done the steps to be able to several times and have checked them.  On the server I can now log in using sql account instead of windows authentication (which I couldn't do before).  I even tried to use the sa account to set up dnn but that did not work.  Are you saying that I should specify the user name and password in the webfig file instead of in the installation.  By the way I am simply using the typical install in the install version of dnn. (newest version)

Greg,

if using SQL Server Express with manually created database and login requires to use SQL2000/2005 connection string template, specifying database name not database mdf file name. HTH.