if you try to connect to the server with ipconfig in cmd, you could acces?
1) Desactive the firewall and try
2) add the page http://xxxx.xx.com/qlikview/index.htm as a secure page in the internet explorer option and try47
3) check that your antivirus is not block nothing
4) restar the qlikview server
5) check you have open the port 4747 and the port 80
Try each one of this point and tell me if you could solve the problem