Internet Explorer 8 on Windows XP SP3 (32 bits). An automatic proxy configuration script is configured. When the browser is started, it fetches the configured URL and keeps the script. Now, I would like to use NTLM authentication on this fetch. Not because I really need authentication, but the config script is in fact constructed by a server-side script and I want to know the username of the logged-in user in that script. Problem is that IE8 asks the user for the username/password, twice even. When I enter it, everything works OK. But I would like to let this authentication to proceed silently, just as when an Intranet site is visited. The server sending the script is on the local Intranet, and when it is visited by IE8 this fact is recognized (shown in the statusbar). What could be going on here? Is it at all possible to make this work? Are there extra things I need to configure?