How to add login user (ASPNET) to MS SQL 2000 Desktop Engine server?

Go to drive:\Program Files\Microsoft SQL Server\80\Tools\binn

Use OSQL, a command line tool.

osql -S servername\instancename -E -q
    --Line numbers will appear
EXEC sp_grantlogin ’machinename\ASPNET’
go

use 
go

EXEC sp_grantdbaccess ’machinename\ASPNET’
go

EXEC sp_addrolemember ’db_owner’, ’machinename\ASPNET’
go