I have a web application on a Windows 2003 server running IIS 6 that I would like to secure using a built in Windows account.<BR><BR>I tried to accomplish this by creating a new windows account and giving that account access to the directory of my web application. When I browse to the web site through a browser, I&#039;m prompted for a Username and PW, and if I supply the credentials of the account I just created, it works perfectly.<BR><BR>However, if I try the same thing from a computer that uses a proxy server to access the Internet, I&#039;m never prompted for a Username and PW and thus, I&#039;m denied access with a 401.3 (Unauthorized due to ACL on resouce) error.<BR><BR>Does anyone know why this works the way I intended on a direct Internet connection, but not through a proxy?<BR><BR>Any suggestions would be appreciated.<BR>-Steve