In windows server 2003 SP1, there is no ICS tab in the dial-up connection's advanced tab. I saw the option in win 2003 without SP, Can u tell me why?

This forum is to discuss TFS install issues hence it is unlikely you'll get answers. You might want to try windows server newsgroups at http://www.microsoft.com/technet/community/en-us/windowsserver/default.mspx . BTW, you might want to check if this site answers your question: http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/security/ws03mngd/33_s3ics.mspx