Hi. I've just downloaded and installed ewido 18.104.22.168 trial. Im trying to perform an update, and the ISA server requires authentication. As you can see from my screenshot, im using the administrator account and im logged on with administrative privileges. Here is my logfile.txt: application start was blocked because of several instances Here is my error.txt: Error: Wrong answer: HTTP/1.1 407 Proxy Authentication Required ( The ISA Server requires authorization to fulfill the request. Access to the Web Proxy service is denied. ) Via: 1.1 JENSEN Proxy-Authenticate: Negotiate Proxy-Authenticate: Kerberos Proxy-Authenticate: NTLM Connection: Keep-Alive Proxy-Connection: Keep-Alive Pragma: no-cache Cache-Control: no-cache Content-Type: text/html Content-Length: 4105 , Position: .\DownloadHttp.cpp, 625 This above block is recursive. I added a trace on the ISA server (called JENSEN) and the report stated that no username was being sent so it was defaulting to 'anonymous'. I have full access to any port when using the Administrator logon, however it seems that the username is not being sent, or not being picked up.