FOR IIS: When you create the site, right click on it, go to properties. Click on the Directory Security tab. Edit "Anonymous access and control". From here, ensure anonymous access is NOT checked and make sure that Integrated Windows authentication IS. Once this done, check your $_SERVER['AUTH_USER'] var and your complete domain\hostname should be listed. If not, view phpinfo() and see if you can find your username in some other similar variable. With the above set, the Windows username should be listed in one of your Global variables. I'm currently using this method on two seperate sites right now.