In order for a Windows login to be able to work in Microsoft Dynamics NAV they must be assigned a role.
Windows logins in Microsoft Dynamics NAV correspond to the Windows users and groups of the Windows domain. If both your domain and clients are running on Windows Vista, Windows 2008, or Windows XP, and SQL Server is running on Windows Vista or Windows Server 2008, you can give Windows users and groups roles within Microsoft Dynamics NAV. You can also make Microsoft Dynamics NAV roles members of Windows security groups.
Click Tools, Security, Roles and the Roles window appears.
Select the role you want.
Click Role, Windows Logins. The Windows Logins window for this role appears displaying a list of the Windows logins that have been given this role.
In the Login ID field, select a new line and click the AssistButton. A window appears listing all of the users that have database logins.
Select the Windows login to which you want to give this role.
Click OK and this Windows login will be added to the list of Windows logins that have this role.
This Windows login has now been given this role for all the companies contained in the current database.
Limiting Roles to Specific Companies for a Login
Modifying Permissions for Roles
Assigning Permissions to Multiple Objects
Removing Roles from Windows Logins