I am wanting my Vb.net application to "know who is logged on" similar to the way SharePoint does. When I start SharePoint 2013, I'm not asked for a username or password, it just "knows" who I am because I've already authenticated through Windows.
Is there a tutorial somewhere that can demonstrate how this is done? All of the users of this application are inside the same Active Directory on a corporate network.
Take a look at https://msdn.microsoft.com/en-us/library/ff650308.aspx, a "How to" implement Forms Authentication with Membership and Active Directory.
This technology is a bit old, but still usable.
A better approach would be to use the new OWIN Identity if you have Azure Active Directory