ASPNET Local Account access to SQL Server 2000

Hello,

I'm not sure if this is the correct forum to address this question, but it deals with setting up a SQL Server login for the ASPNET account found on an IIS 5.0 web server.

I was working with an aspx file I had put together in VS.NET in which the page would render rows of data from a table in the SQL Server 2000 Northwind Database in a datagrid based on the selection of a dropdown list.

When I attempted to 'Build and Browse' the page, I received a Server error message that said, "Login failed for user 'WDO-IT10\ASPNET'". I figured this meant that this local account did not have a login to SQL Server. I assumed that the account would need the login, and would need to be set up as a user to Northwind. The web server IIS 5.0, VS.NET, and SQL Server 2000 Enterprise Eval are on the same machine.

After I set up this account with a Login to SQL Server, I was able to render the page and everything worked despite the fact that I had set up the account as a user to the Pubs database and not Northwind.

How can it be that this local user account can have access to a SQL Server database that it had no user permissions for?
Thanks for your help.

CSDunn